Vehicle stability control system

ABSTRACT

A vehicle stability control system is provided, which includes a movable tongue member and a ratchet mechanism. The movable tongue member is adapted to move between a first tongue position and a second tongue position. The ratchet mechanism is adapted to be mechanically coupled to a movable unsprung mass portion and to a sprung mass portion of a vehicle when the vehicle stability control system is operably installed on the vehicle. The ratchet mechanism comprising a ratchet tooth, such that the ratchet mechanism, is adapted to restrict a movement of the unsprung mass portion away from the sprung mass portion when the tongue member is moved toward the second tongue position and into the ratchet tooth, and wherein the tongue member does not restrict the movement of the unsprung mass portion relative to the sprung mass portion when the tongue member is in the first tongue position.

This application claims the benefit of U.S. Provisional Application No.60/547,703, filed on Feb. 25, 2004, entitled VEHICLE STABILITY SYSTEM,and U.S. Provisional Application No. 60/598,990, filed on Aug. 5, 2004,entitled VEHICLE STABILITY CONTROL SYSTEM, which applications are herebyincorporated herein by reference.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application relates to the following co-pending and commonlyassigned patent applications: U.S. patent application Ser. No. ______,filed herewith, entitled “Vehicle Stability Control System”, havingattorney docket number ABH-001; and PCT Patent Application Serial No.______, filed herewith, entitled “Vehicle Stability Control System”,having attorney docket number ABH-000PCT, which applications are herebyincorporated herein by reference.

TECHNICAL FIELD

The present invention generally relates to improving vehicle safety andcontrollability. More specifically, it relates to affecting the movementof a vehicle suspension system using a vehicle stability control systemduring an emergency or severe cornering maneuver.

BACKGROUND

Sport utility vehicles (SUVs) and pickup trucks have grown in popularityamong consumers in North America. However, such vehicles are usuallymore prone to rollover accidents than cars. This is mostly attributed tothe higher center of gravity for SUVs and trucks as compared to cars.Even SUVs with independent suspension systems and roll stability controlsystems may still have a higher tendency to roll over than most cars.

According to statistics from the year 2000, 62% of all SUV deathsoccurred in rollovers, which is nearly three times the rate for cars(22%). Some government tests indicate that even the most stable SUV ismore likely to rollover than the least stable car. National HighwayTraffic Safety Administration (NHTSA) statistics from 2001 estimatedthat 55% of occupant fatalities in light, single-vehicle crashesinvolved rollover. Furthermore, in 2001, NHTSA estimated that 60% of thefatalities in vans, 63% of fatalities in pickup trucks, and 78% offatalities in SUVs were caused by rollover. According to statistics fromthe year 2002, fatalities in rollover crashes involving SUVs and pickuptrucks accounted for 53% of the increase in traffic deaths. In 2002,about 10,626 people died in rollover crashes in the US, up 4.9% fromabout 10,130 in 2001.

Some rollovers are caused by a vehicle colliding with a curb or abutmentduring a severe turn or during a lateral slide, which is often referredto as a trip rollover. Even a low profile sports car may rollover whencolliding with a trip mechanism. Statistics show that over 90% of triprollovers are caused by a loss of control of the vehicle. Thus, a needexists to improve vehicle stability during severe cornering or emergencymaneuvers.

Some rollovers occur when a driver attempts to avoid a collision with anobject (e.g., another vehicle, a person, an animal, etc.) in the road.When a driver swerves to one side (e.g., right) to avoid an object andthen attempts to regain control of the vehicle and avoid going off theroad by swerving in the opposite direction (e.g., left), this maneuvermay cause a vehicle to rollover as well (even when no trip mechanism isencountered). During such maneuvers where the vehicle's weight isshifted from one side to another, as the vehicle suddenly turns onedirection (e.g., right) and then immediately turns to back in anopposite direction (e.g., left), the vehicle's suspension springs maycontribute to initiating a rollover. This happens because the suspensionsprings have potential energy mechanically stored as a result of beingcompressed by the weight of the vehicle.

Even at level straight condition, the weight of the vehicle partiallycompresses the springs to counteract this weight. This is dramaticallydemonstrated by a person lifting up on a fender of a 6,500-pound vehicleand being able to move one side of the vehicle upward with ease. Whenthe vehicle's weight is transferred to one side (e.g., right), thespring on that side may be further compressed due to the lateralacceleration of the vehicle and the weight shift toward one side. As thevehicle tilts from one side to another side, as in a right-left maneuverfor example, the once compressed spring (during right turning) will pushup on the inside of the vehicle (during the immediately subsequent leftturning). This pushing up on the vehicle's weight is combined with thelateral forces acting on the vehicle due to the turning motion. Thisenergy stored in the spring can propel one side of the vehicle upwardwith very little release of pressure on the spring. The vehicle tiltmovement caused by the inside spring releasing its stored energy createsrotational momentum that is then added to by the lateral or centrifugalforces created by the turning motion of the vehicle and by the forwardmomentum from the vehicle's forward movement.

In a severe turn, the suspension system lets the centrifugal force ofthe turn lower the vehicle on the outside of the turn while at the sametime raising the vehicle on the inside of the turn. The upward forceapplied to the sprung portion of the vehicle by the springs on theinside of the turn is by far the most significant controllable forcecontributing to loss of control of a vehicle. Thus, the tilt movementinitiated by the stored energy in the inside spring may create themomentum needed to initiate a rollover, which the lateral forces of theturning and the forward momentum of the vehicle may bring to fruition.As the vehicle is rotated by this action, it quickly takes less and lesspounds of centrifugal force to progress to the next succeeding degree ofvehicle rotation. The vehicle in less than one second can be put into aprecarious position that can cause the driver to panic as he feels hisinability to control the vehicle. This can quickly cause the driver tolose the ability to avoid other vehicles as well as curbs or abutmentsthat can cause a rollover. Hence, a need exists to improve and/orcontrol the stability of vehicles during such severe turning maneuvers.Such improvements may save thousands of lives each year and reduce thenumber of accidents thereby saving millions of dollars to drivers andinsurance companies.

SUMMARY OF THE INVENTION

The problems and needs outlined above may be addressed by embodiments ofthe present invention. In accordance with one aspect of the presentinvention, a vehicle stability control system is provided, whichincludes a movable tongue member and a ratchet mechanism. The movabletongue member is adapted to move between a first tongue position and asecond tongue position. The ratchet mechanism is adapted to bemechanically coupled to a movable unsprung mass portion and to a sprungmass portion of a vehicle when the vehicle stability control system isoperably installed on the vehicle. The ratchet mechanism comprising aratchet tooth, such that the ratchet mechanism is adapted to restrict amovement of the unsprung mass portion away from the sprung mass portionwhen the tongue member is moved toward the second tongue position andinto the ratchet tooth, and wherein the tongue member does not restrictthe movement of the unsprung mass portion relative to the sprung massportion when the tongue member is in the first tongue position.

In accordance with another aspect of the present invention, a vehiclestability control system is provided, which includes a movable tonguesystem, an electrical triggering device, and a ratchet mechanism. Themovable tongue system includes an electro-mechanical actuator and amovable tongue member. The electro-mechanical actuator is mechanicallycoupled to the tongue member to provide movement of the tongue memberfrom a first tongue position toward a second tongue position. Theelectrical triggering device is adapted to be electrically coupled to asignal generating device. The triggering device is also electricallycoupled to the electro-mechanical actuator. The triggering device isadapted to activate the electro-mechanical actuator based, at least inpart, on an output signal received from the signal generating device.The ratchet mechanism is adapted to be mechanically coupled to a movableunsprung mass portion and to a sprung mass portion of a vehicle when thevehicle stability control system is operably installed on the vehicle.The ratchet mechanism includes a set of ratchet teeth, such that theratchet mechanism is adapted to restrict a movement of the unsprung massportion away from the sprung mass portion when the electro-mechanicalactuator moves the tongue member toward the second tongue position andinto the set of ratchet teeth. The signal generating device may be anacceleration measuring device, wherein the output signal corresponds toa lateral acceleration of the vehicle. The output signal may correspondto a movement of a steering wheel on the vehicle, wherein the signalgenerating device comprises a sensor adapted to measure movement of thesteering wheel. The output signal may correspond to a velocity of thevehicle, wherein the signal generating device comprises a sensor adaptedto measure the velocity of the vehicle. The output signal may correspondto a vehicle body position relative to a ground surface, wherein thesignal generating device comprises one or more sensors adapted tomeasure a tilt angle of a vehicle body relative to the ground surface.The output signal may correspond to a vehicle body position relative toat least one vehicle wheel, wherein the signal generating devicecomprises one or more sensors adapted to measure a tilt angle of avehicle body relative to one or more vehicle wheels. Theelectro-mechanical actuator includes a component selected from the groupconsisting of an electric motor, a solenoid, an electrically-switchablehydraulic valve, a hydraulic actuator, an electrically-switchablepneumatic valve, a pneumatic actuator, an electrically-switchable vacuumvalve, a vacuum-driven actuator, an electrically-switchablepyrotechnic-driven actuator, an electrically-switchableexplosive-charged actuator, an electrically-switchablecompressed-gas-driven actuator, and combinations thereof, for example.The electrical triggering device may include an analog electricalcircuit, wherein the analog electrical circuit includes a capacitor, aresistor, and a transistor. The electrical triggering device may includea microprocessor and an amplifier. The tongue member may have an endprofile with a shape selected from the group consisting of rectangular,partially rounded, notched, pawl shaped, partially beveled, beveled,hook shaped, lip shaped, flat, curved, concave, convex, and combinationsthereof, for example. At least some of the ratchet teeth may have atooth shape selected from the group consisting of rectangular, partiallyrounded, notched, pawl shaped, partially beveled, beveled, hook shaped,lip shaped, flat, curved, concave, convex, and combinations thereof, forexample. At least some of the ratchet teeth may be formed along a curvedpath. At least some of the ratchet teeth may be formed along a linearpath. The ratchet mechanism may include a first slider portion, and asecond slider portion slidably coupled to the first slider portion. Theratchet mechanism may be attached to and part of a shock absorberdevice. The ratchet mechanism may include a ratchet gear extending froma suspension arm and extending circumferentially at least partiallyaround a pivot axis of the suspension arm, wherein the ratchet gear isfixed relative to the suspension arm and adapted to pivot with thesuspension arm about the pivot axis. The ratchet mechanism may include:a first arm; a second arm pivotably coupled to the first arm, at leastpart of the movable tongue system being attached to the second arm; anda tooth arm extending from the first arm, the tooth arm having the setof ratchet teeth thereon, and the tooth arm extending across at leastpart of the movable tongue system when the vehicle stability controlsystem is operably installed on the vehicle. The vehicle stabilitycontrol system may include a roller member attached about a portion ofthe ratchet mechanism, where the roller member is adapted to rotateabout the ratchet mechanism. The ratchet mechanism may include: a pulleymember adapted to be rotatably coupled to the sprung mass portion of thevehicle; a cable having a first end attached to the pulley member, thecable extending from the pulley member, where the pulley member isadapted to spool the cable at least partially around the pulley memberas the pulley member pivots, and the cable being adapted to attach tothe unsprung mass portion of the vehicle to extend between the unsprungmass portion and the pulley member; a pulley spring biasing the pulleymember to pivot in a direction that will spool the cable onto the pulleymember to keep tension on the cable; and a ratchet gear extending fromthe pulley member, the ratchet gear having the set of ratchet teeth,wherein the ratchet gear pivots with the pulley member. The movabletongue member may be adapted to pivot about a tongue member axis as itmoves from the first tongue position toward the second tongue position.The movable tongue member may be adapted to slide as it moves from thefirst tongue position toward the second tongue position.

In accordance with yet another aspect of the present invention, avehicle stability control system is provided, which includes anacceleration measuring device, a movable tongue system, an electricaltriggering device, and a ratchet mechanism. The acceleration measuringdevice is adapted to measure at least a lateral acceleration of avehicle when the vehicle stability control system is operably installedon the vehicle. The movable tongue system includes an electro-mechanicalactuator and a movable tongue member. The electro-mechanical actuator ismechanically coupled to the tongue member to provide movement of thetongue member from a first tongue position toward a second tongueposition. The electrical triggering device is electrically coupled tothe acceleration measuring device. The triggering device is alsoelectrically coupled to the electro-mechanical actuator. The triggeringdevice is adapted to activate the electro-mechanical actuator based, atleast in part, on an output signal received from the accelerationmeasuring device. The ratchet mechanism is adapted to be mechanicallycoupled to a movable unsprung mass portion and to a sprung mass portionof the vehicle when the vehicle stability control system is operablyinstalled on the vehicle. The ratchet mechanism includes a set ofratchet teeth, such that the ratchet mechanism is adapted to restrict amovement of the unsprung mass portion away from the sprung mass portionwhen the electro-mechanical actuator moves the tongue member toward thesecond tongue position and into the set of ratchet teeth. Theacceleration measuring device may include a semiconductor accelerometeradapted to provide a voltage output proportional to a measuredacceleration.

In accordance with still another aspect of the present invention, avehicle stability control system is provided, which includes a firstslider mechanism, an acceleration measuring device, and a triggeringdevice. The first slider mechanism includes: a first slider portion; asecond slider portion slidably coupled to the first slider portion; afirst connector member extending from the first slider portion, thefirst connector member being adapted to be mechanically coupled to atleast one of a sprung mass portion of a vehicle and an unsprung massportion of the vehicle, wherein a vehicle spring is biased between thesprung mass portion and the unsprung mass portion of the vehicle; asecond connector member extending from the second slider portion, thesecond connector member being adapted to be mechanically coupled to atleast one of the unsprung mass portion of the vehicle and the sprungmass portion of the vehicle; a series of teeth formed along the firstslider portion; and a movable tongue system comprising a moveable tonguemember, the movable tongue system being attached to the second sliderportion, the movable tongue system being adapted to position the tonguemember in a first tongue position and a second tongue position. In thefirst tongue position, the tongue member being adapted to be locatedbetween at least some adjacent teeth of the series of teeth, such thatthe first slider portion may slide relative to the second slider portionas the unsprung mass portion moves toward the sprung mass portion of thevehicle, but such that the first slider portion is prevented fromsliding relative to the second slider portion as the unsprung massportion moves away the sprung mass portion of the vehicle. In the secondtongue position, the tongue member does not prevent sliding of the firstslider portion relative to the second slider portion. The accelerationmeasuring device is adapted to output a first electrical signalcorresponding to an acceleration measurement. The triggering device iselectrically connected to the acceleration measuring device and themovable tongue system. The triggering device is adapted to send a secondelectrical signal to the movable tongue system based upon the firstelectrical signal. The vehicle stability control system may furtherinclude a second slider mechanism that is essentially the same as thefirst slider mechanism (e.g., right side mechanism and left sidemechanism). The acceleration measuring device and the triggering devicemay be part of a same electrical component. The triggering device may bepart of the movable tongue system. The first connector member may beadapted to be mechanically coupled to the unsprung mass portion of thevehicle. The second connector member may be adapted to be mechanicallycoupled to the sprung mass portion of the vehicle. The first sliderportion may have an elongated body. The second slider portion may have ahollow elongated body. The first slider portion slidably may mate withthe second slider portion and slide at least partially into the secondslider portion when the unsprung mass portion moves toward the sprungmass portion of the vehicle. At least some of the series of teeth mayhave a top side and a bottom side, where the top side is beveled at anangle relative to an axis of sliding for the first slider portion, andthe bottom side is substantially perpendicular to the axis of slidingfor the first slider portion. At least some of the series of teeth mayhave a top side and a bottom side, where the top side has a curvedprofile, and the bottom side is substantially perpendicular to an axisof sliding for the first slider portion. At least some of the series ofteeth may have a rectangular profile. A distal end of the tongue membermay have a bottom side that is beveled at an angle relative to an axisof sliding for the first slider portion. A distal end of the tonguemember may have a bottom side that has a curved profile. The tonguemember may have a rectangular distal end profile. The movable tonguesystem may include a solenoid for driving movement of the tongue memberbetween the first and second tongue positions.

In accordance with another aspect of the present invention, a vehiclestability control system is provided, which includes an elongated hollowmember, an elongated shaft member, a series of teeth, anelectro-mechanical actuator, a tongue member, and an electrical circuit.The elongated hollow member has a first hole formed in a side thereofand has an open end. The elongated shaft member is slidably engaged intothe open end of the hollow member. The series of teeth is formed alongthe shaft member. The electro-mechanical actuator is attached to thehollow member. The tongue member extends from the electro-mechanicalactuator at the first hole. The electrical circuit includes anacceleration measuring device. The electrical circuit is electricallycoupled to the electro-mechanical actuator. The series of teeth mayinclude a series of recesses formed in the elongated shaft membercomprising a profile shape selected from the group consisting of atriangular shape, a trapezoidal shape, a right angle, a convex curve,and a concave curve. The electro-mechanical actuator may include asolenoid.

In accordance with another aspect of the present invention, a vehiclehaving a vehicle stability control system installed thereon is provided,which includes a vehicle wheel, a vehicle suspension component, aspring, an elongated hollow member, an elongated shaft member, a seriesof teeth, an electro-mechanical actuator, a tongue member, and anelectrical circuit. The vehicle wheel is rotatably coupled to thevehicle at least partially by the vehicle suspension component. Thespring extends between the vehicle suspension component and a sprungmass portion of the vehicle. The elongated hollow member has a firsthole formed in a side thereof and has an open end. The elongated hollowmember is mechanically coupled to the sprung mass portion or the vehiclesuspension component. The elongated shaft member is slidably engagedinto the open end of the hollow member. The elongated shaft member ismechanically coupled to the vehicle suspension component or the sprungmass portion. The elongated shaft member is mechanically coupled to thevehicle suspension component if the elongated hollow member ismechanically coupled to the sprung mass portion. Or, the elongated shaftmember is mechanically coupled to the sprung mass portion if theelongated hollow member is mechanically coupled to the vehiclesuspension component. The series of teeth is formed along the shaftmember. The electro-mechanical actuator is attached to the hollowmember. The tongue member extends from the electro-mechanical actuatorat the first hole. The electrical circuit includes an accelerometerdevice, a microprocessor, and an amplifier. The electrical circuit iselectrically coupled to the electro-mechanical actuator. Theaccelerometer is electrically coupled to an input pin of themicroprocessor. The amplifier is electrically coupled to an output pinof the microprocessor. The vehicle suspension component may be part of arear transaxle assembly. The vehicle suspension component may include alower control arm of an independent suspension system. The sprung massportion may include a vehicle frame. The sprung mass portion may includea vehicle body. The sprung mass portion may include a shock tower.

In accordance with another aspect of the present invention, a method oflimiting a movement of a sprung mass portion of a vehicle relative to anunsprung mass portion of the vehicle is provided. This method includesthe following steps described in this paragraph. The order of the stepsmay vary, may be sequential, may overlap, may be in parallel, andcombinations thereof, if not otherwise stated. A movable tongue memberof a vehicle stability control system moves from a first tongue positiontoward a second tongue position. The tongue member engages teeth of aratchet mechanism, the ratchet mechanism being part of the vehiclestability control system. The ratchet mechanism is mechanically coupledto the unsprung mass portion and to the sprung mass portion of thevehicle. When the tongue member engages the teeth, the ratchet mechanismrestricts a movement of the unsprung mass portion away from the sprungmass portion. The tongue member does not restrict the movement of theunsprung mass portion relative to the sprung mass portion when thetongue member is in the first tongue position.

In accordance with yet another aspect of the present invention, a methodof limiting expansion of a spring member on a vehicle is provided. Thismethod includes the following steps described in this paragraph. Theorder of the steps may vary, may be sequential, may overlap, may be inparallel, and combinations thereof, if not otherwise stated. The springmember is biased between a sprung mass portion of the vehicle and anunsprung mass portion of the vehicle. A tongue member is moved from afirst tongue position toward a second tongue position. A set of ratchetteeth is engaged with the tongue member as the tongue member is movedtoward a second tongue position. The ratchet teeth are part of a ratchetmechanism. The ratchet mechanism being mechanically coupled to thesprung mass portion and to the unsprung mass portion of the vehicle. Amovement of the unsprung mass portion away from the sprung mass portionis restricted when the tongue member is moved toward the second tongueposition and into the set of ratchet teeth. The moving of the tonguemember from the first tongue position toward the second tongue positionmay be performed after steps comprising: receiving an output signal froma signal generating device; determining whether the output signal meetsor exceeds a predetermined threshold level; and if the output signalmeets or exceeds the predetermined threshold level, activating anelectro-mechanical actuator, wherein the electro-mechanical actuator isused for the moving of the tongue member. The signal generating devicemay be an accelerometer, and the method may further include measuring alateral acceleration of the vehicle with the accelerometer, wherein theoutput signal corresponds to a lateral acceleration of the vehicle. Themethod may further include measuring a velocity of the vehicle with asensor, wherein the activating of the electro-mechanical actuator isonly performed if the velocity is above a predetermined velocity level.The method may further include measuring a movement of a steering wheelon the vehicle with a sensor, wherein the output signal corresponds tothe movement of the steering wheel as a function of time. The method mayfurther include measuring a velocity of the vehicle with a sensor,wherein the output signal corresponds to the movement of the steeringwheel as a function of time. The method may further include measuring atilt angle of a body of the vehicle relative to a ground surface withone or more sensors, wherein the output signal corresponds to the tiltangle of the vehicle. The method may further include measuring a tiltangle of a body of the vehicle relative to one or more vehicle wheelswith one or more sensors, wherein the output signal corresponds to thetilt angle of the vehicle. The electro-mechanical actuator may include acomponent selected from the group consisting of an electric motor, asolenoid, an electrically-switchable hydraulic valve, a hydraulicactuator, an electrically-switchable pneumatic valve, a pneumaticactuator, an electrically-switchable vacuum valve, a vacuum-drivenactuator, an electrically-switchable pyrotechnic-driven actuator, anelectrically-switchable explosive-charged actuator, anelectrically-switchable compressed-gas-driven actuator, and combinationsthereof, for example. The determining whether the output signal meets orexceeds the predetermined threshold level may be performed by anelectrical circuit comprising a component selected from the groupconsisting of a microprocessor, a capacitor, a resistor, a transistor,an analog electrical circuit, an analog-to-digital converter, adigital-to-analog converter, an amplifier, and combinations thereof. Atleast some of the ratchet teeth may be formed along a curved path. Atleast some of the ratchet teeth may be formed along a linear path. Theratchet mechanism may include a first slider portion, and a secondslider portion slidably coupled to the first slider portion. The ratchetmechanism may be attached to and part of a shock absorber device. Theratchet mechanism may include a ratchet gear extending from a suspensionarm and extending circumferentially at least partially around a pivotaxis of the suspension arm, wherein the ratchet gear is fixed relativeto the suspension arm and adapted to pivot with the suspension arm aboutthe pivot axis. The ratchet mechanism may include a first arm; a secondarm pivotably coupled to the first arm, at least part of the movabletongue system being attached to the second arm; and a tooth armextending from the first arm, the tooth arm having the set of ratchetteeth thereon, and the tooth arm extending across at least part of themovable tongue system when the vehicle stability control system isoperably installed on the vehicle.

In accordance with still another aspect of the present invention, amethod of limiting expansion of a spring member on a vehicle isprovided. This method includes the following steps described in thisparagraph. The order of the steps may vary, may be sequential, mayoverlap, may be in parallel, and combinations thereof, if not otherwisestated. Lateral acceleration of the vehicle is measured. It isdetermined whether the lateral acceleration of the vehicle exceeds apredetermined threshold level. If the lateral acceleration exceeds thepredetermined threshold level, then for a predetermined period of time,allowing the spring member to be compressed when the unsprung massportion moves toward the sprung mass portion, but not allowing thespring member to expand. The measuring lateral acceleration may beperformed by an accelerometer. The determining whether the lateralacceleration of the vehicle exceeds a predetermined threshold level maybe performed by a microprocessor. The determining whether the lateralacceleration of the vehicle exceeds a predetermined threshold level maybe performed by analog electrical circuitry. The analog electricalcircuitry may include a resistor, a capacitor, and a transistor. In oneapplication, the method may be performed only if the vehicle is movingat a speed greater than a predetermined speed level, and wherein themethod further comprises measuring and monitoring the speed of thevehicle. The predetermined threshold level for lateral acceleration maybe about 0.2 g (or about 6.4 ft/sec²) and the predetermined speed levelis about 30 miles per hour. The predetermined period of time may beabout 1 second, for example. The method may include allowing the springmember to be compressed when the unsprung mass portion moves toward thesprung mass portion, but not allowing the spring member to expand, whichincludes: activating an electro-mechanical actuator of a movable tonguesystem; and using the electro-mechanical actuator, moving a tonguemember of the movable tongue system toward a first slider portion of afirst slider mechanism and into a series of teeth formed along the firstslider portion, wherein the first slider portion is slidably coupled toa second slider portion of the first slider mechanism, and wherein themovable tongue system is attached to the second slider portion.

In accordance with another aspect of the present invention, a method ofimproving vehicle stability during abrupt turning maneuvers is provided.This method includes the following steps described in this paragraph.The order of the steps may vary, may be sequential, may overlap, may bein parallel, and combinations thereof, if not otherwise stated. Alateral acceleration measurement of a vehicle is obtained. If thelateral acceleration measurement exceeds a predetermined lateralacceleration level, then for a predetermined period of time, anelectro-mechanical actuator is activated. The electro-mechanicalactuator is part of a moveable tongue system. The moveable tongue systemfurther includes a tongue member. Using the electro-mechanical actuatorwhen activated, the tongue member is driven against a first sliderportion of a first slider mechanism at a location upon a path ofmovement for a series of teeth formed along the first slider portion.The first slider portion is slidably coupled to a second slider portionof the first slider mechanism. The movable tongue system is attached tothe second slider portion. The first slider mechanism is mechanicallycoupled between a sprung mass portion and an unsprung mass portion ofthe vehicle. A vehicle wheel is rotatably coupled to the unsprung massportion. A spring member is biased between the sprung mass portion andthe unsprung mass portion of the vehicle. When the tongue member isdriven against the first slider portion and when the tongue memberengages into the series of teeth, the spring member is prevented fromexpanding. The tongue member may be driven against the first sliderportion and when the tongue member engages into the series of teeth,allowing the spring member to be compressed. The obtaining the lateralacceleration measurement may be performed by an acceleration measuringdevice comprising an accelerometer. The determining if the lateralacceleration measurement exceeds the predetermined lateral accelerationlevel may be performed by a triggering device comprising amicroprocessor.

The foregoing has outlined rather broadly features of the presentinvention in order that the detailed description of the invention thatfollows may be better understood. Additional features and advantages ofthe invention will be described hereinafter, which form the subject ofthe claims of the invention. It should be appreciated by those skilledin the art that the conception and specific embodiment disclosed may bereadily utilized as a basis for modifying or designing other structuresor processes for carrying out the same purposes of the presentinvention. It should also be realized by those skilled in the art thatsuch equivalent constructions do not depart from the spirit and scope ofthe invention as set forth in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The following is a brief description of the drawings, which illustrateexemplary embodiments of the present invention and in which:

FIGS. 1A-4 illustrate a fish-hook maneuver for a stock test vehiclewithout using an embodiment of the present invention;

FIGS. 5-7 show various portions and various views of a firstillustrative embodiment of the present invention;

FIGS. 8A-11 illustrate a fish-hook maneuver test while using the firstembodiment of the present invention;

FIG. 12 shows a ratchet mechanism of a second illustrative embodiment ofthe present invention;

FIGS. 13-16 show various views of a third illustrative embodiment of thepresent invention;

FIGS. 17 and 18 are simplified views of ratchet mechanisms to show twoillustrative ways to prevent the shaft member from being pulledcompletely out of the hollow member;

FIGS. 19A-19D show enlarged views of the teeth on the shaft membermoving relative to the tongue member for the first embodiment(corresponding to FIG. 7) during a use of the system;

FIGS. 20A-20D illustrate a set of teeth and a tongue member of a fourthillustrative embodiment of the present invention;

FIGS. 21A-21D illustrate a set of teeth and a tongue member of a fifthillustrative embodiment of the present invention;

FIGS. 22A-22E show some illustrative examples for teeth patterns thatmay be implemented in an embodiment of the present invention;

FIGS. 23A-23E show some illustrative examples for cross-sections oftongue members that may be implemented in an embodiment of the presentinvention;

FIGS. 24A-24Q show some illustrative examples for end profiles of tonguemembers that may be implemented in an embodiment of the presentinvention;

FIG. 25 illustrates a set of teeth and a tongue member of a sixthillustrative embodiment of the present invention;

FIG. 26 is a side view showing part of a seventh embodiment of thepresent invention;

FIG. 27 shows a system of an eighth embodiment of the present inventionoperably installed on a vehicle;

FIG. 28 shows a system of a ninth embodiment of the present inventionoperably installed on a vehicle;

FIG. 29 shows a system of a tenth embodiment of the present inventionoperably installed on a vehicle;

FIG. 30 is a side view of a slider mechanism and movable tongue systemof an eleventh embodiment of the present invention;

FIGS. 31-34 show simplified schematics for components of the firstembodiment;

FIG. 35 is a detailed electrical schematic for components of the firstembodiment;

FIG. 36 is a simplified schematic for components of an embodiment of thepresent invention;

FIGS. 37A-37C illustrate a shaft member with a single tooth and a tonguemember of a twelfth illustrative embodiment of the present invention;

FIG. 38 illustrates a shaft member with a single tooth and a tonguemember of a thirteenth illustrative embodiment of the present invention;and

FIG. 39 shows a system of a fourteenth embodiment of the presentinvention operably installed on a vehicle.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Referring now to the drawings, wherein like reference numbers are usedherein to designate like or similar elements throughout the variousviews, illustrative embodiments of the present invention are shown anddescribed. The figures are not necessarily drawn to scale, and in someinstances the drawings have been exaggerated and/or simplified in placesfor illustrative purposes only. One of ordinary skill in the art willappreciate the many possible applications and variations of the presentinvention based on the following illustrative embodiments of the presentinvention.

Generally, an embodiment of the present invention may be used to improvethe handling and stability of a vehicle during a severe turning maneuveror an emergency steering maneuver. In a preferred embodiment, a systemof the present invention may be activated when a severe turning maneuveror an emergency steering maneuver is sensed. Thus, during most normaldriving situations the system would simply monitor certain conditions ofthe vehicle and remain inactive (i.e., not interfering with the stocksuspension functions of the vehicle). These and other aspects ofillustrative embodiments of the present invention will be describednext.

FIGS. 1A-4 illustrate a fish-hook maneuver, which is similar to adynamic rollover testing maneuver adopted by the National HighwayTraffic Safety Administration (NHTSA) in 2003 to evaluate and ratevehicles for rollover potential. FIGS. 1A, 2A, and 3A illustrate themovement of the vehicle's steering wheel 20 during a fish-hook maneuver.FIGS. 1B, 2B, and 3B illustrate rear views of a typical sport utilityvehicle (SUV) 22 (without using an embodiment of the present invention)corresponding to the different stages of the fish-hook maneuver andcorresponding to the steering wheel positions of FIGS. 1A, 2A, and 3A.FIG. 4 is a plan view illustrating the motion of the SUV 22 during thefish-hook maneuver.

An actual fish-hook maneuver rollover test is typically performed at atesting facility having a large, flat, level skid pad area with astraight runway leading to the skid pad area. Also, the vehicle 22typically has outriggers (not shown) installed thereon to prevent thevehicle 22 from actually rolling over when a rollover would otherwiseoccur. To perform a fish-hook maneuver, the test driver begins bydriving along a straight line (see e.g., line 24 of FIG. 4) at somepredetermined speed (e.g., 35-50 mph). Thus, at this stage the steeringwheel 20 is held straight, as shown in FIG. 1A, and the vehicle 22 islevel relative to the ground surface 26, as shown in FIG. 1B. In thisexample, the vehicle 22 is traveling at 45 mph.

Next, the steering wheel 20 is quickly and abruptly (preferably as fastas humanly possible) turned to the right 180 degrees, as shown in FIG.2A. In this fish-hook test, the driver removes his foot from the gaspedal at the same time the right turn is initiated, and the gas andbrake pedals are not pressed throughout the remainder of the fish-hookmaneuver. Often the steering wheel 20 will have a knob 28 pivotablyattached thereto, as shown in FIGS. 1A, 2A, and 3A, during testing toallow the driver to turn the steering wheel 20 faster. As the vehicle 22turns to the right side, the centrifugal force of the turn exerts alateral acceleration on the vehicle body. This centrifugal force causesthe vehicle body to lean and tilt downward on the left side, compressingthe rear springs on the left side. This is illustrated in FIG. 2B. Oftenthe right side will be raised during this tilting, as shown in FIG. 2B.Note the tilt angle of the SUV 22 in FIG. 2B and note that the center ofgravity 30 is raised (as compared to FIG. 1B). In other vehicles, thecenter of gravity 30 (at this stage) may be raised, lowered, or remainabout the same, depending on the springs and shocks of the vehicle 22.

Just as the steering wheel 20 reaches the 180 degree position shown inFIG. 2A, the driver immediately and quickly turns the steering wheel 20as far as possible in the opposite direction (e.g., about 450 degrees,depending on the vehicle), as shown in FIG. 3A. Referring again to FIG.4, the vehicle 22 then proceeds to turn left until it stops. As thevehicle 22 begins to turn left, the weight of the sprung mass of thevehicle 22 (e.g., frame and body) is rapidly shifted to the right side,as shown in FIG. 3B. This reverses the downward force that wascompressing the left-side springs, and the left-side springs beginexpanding towards the preloaded level (see FIG. 1B). Hence, thepotential energy that was stored in the left-side spring is quicklyreleased as the weight of the vehicle is quickly shifted toward theright side. The left-side spring then pushes up on the left side of thevehicle frame (on the inside of the turn), only limited by the dampeningeffect of the shock absorbers and the counter spring force of theanti-sway bar (if any). This force exerted on the left side of thevehicle 22 adds to the weight transfer and tilting toward the right sidecaused by the centrifugal force. This spring force from the left sidehelps to overcome the inertia of the prior left-side weight transfer tobuild momentum in the tilting toward the right side. This tiltingmomentum can then be easily maintained by the centrifugal force towardthe right side, as well as the forward momentum of the vehicle 22, andgenerate a rollover situation. Note also in FIG. 3B that the center ofgravity 30 of the vehicle is further raised. Raising the center ofgravity 30 of a vehicle 22 generally worsens its handling abilities anddecreases its stability. As the center of gravity 30 is raised, themoment arm between the center of gravity 30 and the tilt center point isincreased, which makes it easier to roll over the vehicle 22 for a givencentrifugal force acting on the center of gravity 30 (i.e., moreleverage provided).

There are different types of fish-hook maneuver tests, including theRoll Rate Feedback Fishhook and the Fixed Timing Fishhook (amongothers). The most common scenario leading to untripped rollover,according to NHTSA is when a driver, through fatigue or distractionallows the right wheels to drop off-the right pavement edge. The driverattempts to get back on the paved roadway by abruptly steering to theleft. The lip between the pavement and shoulder may require asubstantial steer angle to rise out of the drop-off lip. Once thevehicle overcomes the lip, the driver may not anticipate the quickdirectional change to the left once the vehicle is on full pavement. Thedriver then rapidly counter-steers to the right in an attempt torecover. The Roll Rate Maneuver format takes into account an individualvehicle's handling characteristics, while the Fixed Time format doesnot. The Roll Rate format, according to NHTSA reports, appears to bemore acceptable because it accounts for the different weight andhandling characteristics of each make and model. Both maneuvers may beconducted with an automated steering controller, and the reverse steerof the fish-hook maneuver may be timed to coincide with the maximum rollangle to create an objective “worst case.”

In the example of FIGS. 1A-4, an embodiment of the present invention maybe used to prevent the left-side springs from adding to and/orinitiating a tilt movement toward the right side. In addition, anembodiment of the present invention may be used to effectively stiffenthe suspension and lower the center of gravity 30 of the vehicle 22,both of which may greatly improve the handling and stability of thevehicle 22 (especially an SUV or truck having a relatively high centerof gravity compared to most cars).

FIGS. 5-7 show various portions and various views of a firstillustrative embodiment of the present invention. FIG. 5 is a rear viewof an SUV 22 having a vehicle stability control system 32 installedthereon, in accordance with the first illustrative embodiment of thepresent invention. Portions of the vehicle 22 are not shown or are shownin dashed lines to better illustrate the system 32 of the firstembodiment. In FIG. 5, the following portions of the vehicle 22 areshown: part of the frame 34, the rear transaxle 36, the rear tires 38,the rear shocks 40, and a cross-section view of the rear springs 42.

A system 32 of a preferred embodiment includes a signal generatingdevice, a triggering device, a movable tongue system, and a ratchetmechanism. In the first embodiment, an electrical device 44 includes asignal generating device and a triggering device. The electrical device44 is electrically coupled to a movable tongue system 46. The signalgenerating device of the first embodiment includes an accelerationmeasuring device, such as a semiconductor accelerometer, for example.The accelerometer of the first embodiment is installed in a position tooutput a voltage signal corresponding to a lateral acceleration of thevehicle 22 (due to centrifugal force). As will be discussed below, othersignal generating devices may be implemented in other embodiments of thepresent invention. The triggering device of the first embodimentincludes a microprocessor and amplifiers. A voltage output of theaccelerometer corresponding to a lateral acceleration measurement iselectrically connected to an input of the microprocessor. Themicroprocessor includes an A/D converter and software. The A/D converterconverts the analog signal output from the accelerometer to acorresponding digital signal. The software residing in themicroprocessor includes logic to evaluate the lateral accelerationvalues. If the lateral acceleration meets or exceeds a predeterminedthreshold level (e.g., for a certain number of cycles), then themicroprocessor changes its output to the amplifiers. The amplifiersraise the voltage and current to a level to activate theelectro-mechanical actuator 48 of the movable tongue member 46(described below). More details about the electrical device 44 will bedescribed below, as well as some possible variations on the signalgenerating device and the triggering device.

The movable tongue system 46 is attached to the ratchet mechanism 52 inFIGS. 5-7. The movable tongue system of the first embodiment includes amovable tongue member 54 and an electro-mechanical actuator 48. A cover50 of the movable tongue system 46 is broken away in FIGS. 6 and 7 toreveal the components therein. There are many possible variations andalternatives for the tongue member 54 and the electro-mechanicalactuator 48, as will be discussed below.

FIGS. 6 and 7 are cross-section views showing the movable tongue system46 and the ratchet mechanism 52 of the first illustrative embodiment forthe left side of the vehicle 22 (see also in FIG. 5). Theelectro-mechanical actuator 48 of the first embodiment includes asolenoid. The solenoid 48 is electrically coupled to the electricaldevice 44 (see FIG. 5), and is mechanically coupled to the tongue member54 (see FIGS. 6 and 7). The solenoid 48 is used to move the tonguemember 54 from a first tongue position 61 to or toward a second tongueposition 62. In FIG. 6, the tongue member 54 is shown in the firsttongue position 61 (retracted), and the tongue member 54 of FIG. 7 isshown in the second tongue position 62 (engaging the teeth 64). When thesolenoid 48 is not activated by the electrical device 44, a tonguespring 66 biases the tongue member 54 to or toward the first tongueposition 61 (see FIG. 6).

The ratchet mechanism 52 of the first embodiment has a first sliderportion 71 and a second slider portion 72. The second slider portion 72in this case is an elongated hollow member having an open end 74. Thefirst slider portion 71 in this case is an elongated shaft member. Aseries of teeth 64 are formed along the shaft member 71. These teeth 64are formed by a series of recesses 76 formed in the elongated shaft 71.In the first embodiment, the teeth 64 have a beveled side and a flatside, to provide the ratcheting function for this case. The distal endof the tongue member 54 for the first embodiment has arectangular-shaped profile and is adapted to fit into the recesses 76between the teeth 64, as shown in FIG. 7. When the solenoid 48 drivesthe tongue member 54 toward the second tongue position 62 and into theseries of teeth 64, the ratchet mechanism 52 is permitted to becompressed but is restricted from expanding.

Still referring to FIGS. 6 and 7, a first connector member 81 isattached to and extends from the first slider portion 71. Similarly, asecond connector member 82 is attached to and extends from the secondslider portion 72. In this example, the second connector member 82 is abolt extending through an end of the elongated hollow member 72 and heldin place by a corresponding nut. The first connector member 71 in thisexample is a Heim joint connector bolted to a bracket extending from anend of the shaft member 71. Referring again to FIG. 5, the secondconnector member 82 is bolted to a frame bracket 84, which is attachedto a frame rail 34 of the vehicle 22. In other embodiments, the framebracket 84 may be an integral part of the vehicle frame 34. The framebracket 84 preferably bolts to the frame 34 in an aftermarketinstallation. However, the frame bracket 84 may be attached to the frame34 in other ways (e.g., welded). In some embodiments, a frame bracket 84may not be needed (e.g., when ratchet mechanism 52 attaches directly toframe, body, or shock tower of the vehicle 22). The first connectormember 81 of the first embodiment is bolted to a leaf spring bracket 86,which is a suspension component in this case. The SUV 22 of FIG. 1 hasleaf springs 42. Only cross-section views of the leaf springs 42 areshown in FIG. 5. As is a typical configuration, a vehicle shock absorber40 (dampener) is also attached between the vehicle frame 34 and the leafspring bracket 86. Thus, the ratchet mechanism 52 is mechanicallycoupled between a sprung mass portion of the vehicle 22 and a movableunsprung mass portion of the vehicle 22. In this case, the unsprung massportion includes a rear transaxle assembly 36, as is common on many SUVsand trucks.

It should also be noted that the ratchet mechanism 52 of the firstembodiment may be flipped. That is, the shaft member 71 may bemechanically coupled to the sprung mass portion of the vehicle 22, andthe hollow member 72 may be mechanically coupled to the unsprung massportion in other embodiments.

Still referring to FIGS. 5-7, the tongue member 54 extends through aside hole 88 formed in the side of the elongated hollow member 72 whenthe tongue member 54 is in the second tongue position 62 (see FIG. 7).Referring to FIG. 6, when the tongue member 54 is retracted by thetongue spring 66 expanding (i.e., not extending past the side hole 88 inthis case) (when the solenoid 48 is not activated), the first sliderportion (shaft member 71) is free to slide into and out of the secondslider portion (elongated hollow member 72). Thus, in the configurationof FIG. 6, the system 32 of the first embodiment does not hinder themovement and motion of the unsprung mass portion relative to the sprungmass portion of the vehicle 22, and the shaft member 71 freely slideswithin the elongated hollow member 72, as a slider mechanism. But whenthe solenoid 48 is activated (energized) to drive the tongue member 54toward the second tongue position 62, the tongue member 54 slides into arecess 76 and engages the series of teeth 64. The beveling of the teeth64 allow a sufficient compressive force exerted on the ratchet mechanism52 to force the tongue member 54 toward the first tongue position 61 asit slides along the beveled side of a tooth 64. But the tongue member 54engaging the flat side of the tooth 64 (see FIG. 7) prevents the shaftmember 71 from being pulled out of the hollow member 72. The functionsof these actions will be explained next with regard to FIGS. 8A-11 andcontinuing reference to the first embodiment of FIGS. 5-7.

FIGS. 8A-11 illustrate the same fish-hook maneuver test described abovewith reference to FIGS. 1A-4, but with the use of the first embodimentof the present invention. As will be shown, having the system 32 of thefirst embodiment operably installed on the vehicle 22, as shown in FIG.5, improves the stability and controllability of the vehicle 22. In thisexample, the system 32 is only installed on the rear suspension of thevehicle 22. In other embodiments (not shown), the system 32 may beinstalled on the front and rear suspensions, or only on the frontsuspension, for example. FIGS. 8A and 8B are the same as FIGS. 1A and1B, but with the system 32 on and not activated yet. In other words, thesolenoid 48 is not activated and the tongue member 54 is in the firsttongue position 61 (retracted), as shown in FIG. 6. For purposes ofcomparison, the same vehicle 22 is again traveling at 45 mph for thefish-hook maneuver, but with the system 32 of the first embodimentoperably installed thereon. When the system is on, the accelerometer iscontinuously measuring the lateral acceleration of the vehicle 22(corresponding to the centrifugal force experienced by the vehicle 22).Also, the microprocessor is continuously receiving and processing outputsignals from the accelerometer, to determine if the lateral accelerationhas met or exceeded the predetermined threshold level. During normaldriving conditions, the lateral acceleration rarely, if ever, exceedsthe predetermined threshold level while the vehicle is traveling at highspeeds (e.g., above 30-40 mph).

Referring now to FIGS. 9A, 9B, and 11, the steering wheel 20 is abruptlyturned to the right 180 degrees. When the steering wheel 20 is quicklyturned 180 degrees while the vehicle 22 is traveling 45 mph, forexample, the centrifugal forces exerted on the vehicle body willgenerate a lateral acceleration measurement in the accelerometer thatexceeds the threshold level, and thus, the system 32 is activated(triggered). The microprocessor then activates the solenoid 48 (via theamplifiers) as long as the lateral acceleration exceeds about 0.2 g, forexample, and then for a predetermined amount of time (e.g., about 1second). In other embodiments and applications, the lateral accelerationfor activating the system 32 may be increased or decreased, and thepredetermined amount of time may be increased or decreased, as needed ordesired. The activated solenoid 48 drives tongue member 54 toward thesecond tongue position 62 (see FIG. 7). In the first embodiment, bothsides are activated. On each side, the tongue member 54 engages theteeth 64 on the shaft member 71, and the ratchet mechanism 52 begins tolimit the movement of the suspension. When the system 32 is activated,the suspension on each side is permitted to further compress, but thesuspension is prevented from expanding on each side. In other words, thesprung mass portion is permitted to move toward the unsprung massportion, but the sprung mass portion is not permitted to move away fromthe unsprung mass portion by the ratchet mechanisms 52. FIG. 9B may bethe same or similar to FIG. 2B. The system 32 has the most effect on thevehicle 22 when the driver abruptly changes direction of steering, aswhen a driver in an emergency situation counter-steers while trying toreturn to his/her lane, trying to avoid going off the road, and/ortrying to avoid hitting another object (e.g., on coming traffic, anothercar, a person, an animal, a tree, a barrier, a wall, a guardrail, aditch, etc.).

Returning again to the fish-hook maneuver at FIGS. 10A-11, the drivernext turns the steering wheel 20 immediately and quickly in the oppositedirection (left in this case) as far as possible (worst case). As thecentrifugal force acting on the center of gravity 30 reverses directionand as the vehicle body weight is transferred toward the right side, theright side of the suspension begins to be compressed, as shown in FIG.10B. Because the system is activated and the ratchet mechanisms 52 arepreventing expansion of the rear suspension, the left side of the rearsuspension is prevented from expanding and the left side of the vehicle22 is not pushed upward by the left-rear leaf spring 42. Thus, thesystem 32 prevents the left-rear spring 42 from adding to thecentrifugal forces tilting the vehicle 22 to the right side. Also, thesystem 32 prevents the center of gravity 30 from being raised (compareFIG. 10B to FIG. 3B), which improves the handling and stability of thevehicle 22 during this extreme maneuver. Furthermore, by keeping thesprings 42 compressed, the rear suspension is effectively stiffenedbecause the spring rate is increased as the springs 42 are compressed.By stiffening the rear suspension and lowering the center of gravity 30,the SUV 22 takes on handling characteristics more like a sports car. Theresult is better handling and more stability (as compared to the stocksuspension).

Testing the system of the first embodiment on a 1991 Ford Explorer (thefirst test vehicle) revealed numerous advantages and benefits. For thisfirst test vehicle, one leaf of the leaf spring was removed on each sideof the rear suspension. The testing was performed by a unbiased andexperienced professional test driver at the Continental Proving Groundsin Uvalde, Texas. Without the system 32 of the first embodiment on, thefirst test vehicle 22 reached rollover during a fish-hook maneuver at 45mph (see FIG. 3B). During the testing, the first test vehicle 22 wasprevented from actually rolling over by safety outriggers extending fromthe sides of the vehicle 22 (i.e., outriggers were touching the groundand inside wheels were off the ground). With the system 32 turned on,the first test vehicle 22 does not reach rollover during a fish-hookmaneuver at 45 mph (see FIG. 10B) and the vehicle 22 is stable. Acomparison of the paths traveled with and without the system 32 turnedon (compare FIGS. 4 and 11) reveals a dramatic difference in the turningradius 90. In FIG. 4, without the system 32 turned on, the vehicle 22had a turning radius 90 between about 131 feet and about 141 feet. Incontrast, the results shown in FIG. 11 with the system 32 turned on,provided a turning radius 90 between about 79 feet and about 115 feet.

Further tests of the first test vehicle 22 at higher speeds with thesystem 32 turned off were not performed because the vehicle 22 wasalready reaching rollover at 45 mph. However, further tests of the firsttest vehicle 22 with the system 32 turned on were performed at muchhigher speeds, without rollover. As the speeds increased, the turningradius 90 tended to decrease dramatically and then slowly increasebecause the vehicle 22 began to experience rear wheel sliding, ratherthan rollover, which caused the back end of the vehicle 22 to comearound at a sharper angle. Performing the same fish-hook maneuver testwith the first test vehicle 22 at 50, 55, 60, 65, and 70 mph providedturning radiuses of about 82, 19, 24, 26, and 32 feet, respectively.Even at up to 70 mph, the first test vehicle 22 with the system 32turned on did not reach rollover. Instead of rolling over at such higherspeeds, the first test vehicle 22 tended to lose traction at the reartires 38 and the rear tires 38 would slide, which is what a sports carwould do in such a maneuver at high speed.

One phenomena discovered during testing of the first embodiment of FIGS.5-7 on the first test vehicle 22 was that the leaf spring suspension ofthis vehicle 22 allowed the rear transaxle 36 to shift left (and right)relative to the vehicle frame and body during hard cornering. As aresult, the outside tire of the vehicle 22 had a tendency to rub againstthe elongated hollow member 72 of the first embodiment (see FIG. 5).This created a braking effect on the rear outside tire during hardcornering, whether the system 32 was turned on or not, which was alsoimproving the cornering of the first test vehicle 22 (as compared to thesystem 32 not being installed on the vehicle 22). It was also found thatthe tire 38 engaging the hollow member 72 kept the suspension frommoving lateral any farther.

FIG. 12 illustrates a second illustrative embodiment of the presentinvention, which may be used to address this situation where the rearsuspension is permitted to shift laterally during hard cornering. Thesystem 32 of the second embodiment in FIG. 12 is similar to the firstembodiment of FIGS. 5-7, except that a roller member 92 has been added.The roller member 92 is rotatably coupled to the elongated hollow member72 in the second embodiment, and is permitted to freely rotate about thehollow member 72. Thus, if the tire 38 adjacent to the roller member 92is pressed against the system 32 of the second embodiment, the tire 38will engage the roller member 92. Then, the roller member 92 will allowthe tire 38 to continue rolling with less interference from the system32. It is contemplated that the roller member 92 may have apredetermined amount of rotational friction to allow the roller member92 to provide a slight braking action on the tire 38, when the tire 38engages the roller member 92. It is also contemplated that the rollermember 92 may have a controllable and/or variable amount of rotationalfriction to provide a more advanced braking of the tire 38, when thetire engages the roller member 92. In many embodiments and applicationsof the present invention, however, a roller member 92 may not be desiredor may not be needed.

The shaft member 71 and the hollow member 72 of the first illustrativeembodiment of FIGS. 5-7 each have a generally square cross-sectionshape. In the first illustrative embodiment, which was installed andused on the first test vehicle 22, the shaft member 71 has across-section of about 2 inches by 2 inches. If desired, an embodimentof the present invention may be easily modified and/or installeddifferently on a vehicle 22 to prevent the tires 38 from rubbing againstthe system 32. For example, the first embodiment may be installedparallel to the shock absorber 40 (see FIG. 5). As another example, thefirst embodiment may be made with a thinner shaft member 71 (e.g., 1inch by 2 inches, rectangular shaped). It should also be noted that theshaft member 71 of an embodiment may have any suitable cross-sectionshape, including (but not limited to) the following shapes: circular,rounded, rounded comers, square, rectangular, triangular, pentagonal,hexagonal, octagonal, and arbitrarily shaped, for example. The size,proportions, and dimensions of the shaft member 71 may vary for otherembodiment as well. Correspondingly, the inside portion of the hollowmember 72 will preferably mate with the shaft member 71 to providesmooth sliding. However, the inside portion of the hollow member 72 mayhave a slightly different shape than the shaft member 71 (e.g.,additional slot). The outside shape of the hollow member 72 will oftenbe the same as, about the same as, or similar to the inside shape of thehollow member 72 (e.g., an extruded tubular member used to construct thehollow member 72). The outside shape of the hollow member 72 may have adifferent shape than the inside of the hollow member 72.

FIGS. 13-16 show various views of a third illustrative embodiment of thepresent invention. A 2005 Ford Explorer (“the second test vehicle”) wastested with the third embodiment installed thereon. The third embodimentis similar to the first embodiment, except that the shaft member 71 ismade thinner to provide clearance for the tires 38, and the system 32 isadapted to be mounted on a different vehicle 22 (i.e., the second testvehicle). The 2005 Ford Explorer has independent rear suspension withcoil springs 42, rather than the leaf spring suspension with the solidrear transaxle of the first test vehicle. This illustrates that anembodiment of the present invention may be adapted to work with anyvehicle and with any type of suspension system, including (but notlimited to): solid axle, independent suspension systems, McPhersonStruts suspension, double wishbone, trailing arm, three link, Packardarm, progressive rate springs, uniform rate springs, coil over shocks,torsion bar, and others, for example. The shaft member 71 of the thirdembodiment has a rectangular cross-section that has dimensions of about1 inch by 2 inches. The system of the third embodiment provides enoughclearance for the tires 38 so that the tires should never touch thesystem 32 during use.

Initial testing of the third embodiment on the second test vehicle 22performing fish-hook maneuvers up to 40 mph (as described regardingFIGS. 1A-4 above) has revealed dramatic improvements in handling,stability, and controllability, as the first embodiment did on the firsttest vehicle. The second test vehicle 22 includes a roll stabilitycontrol system, as a feature of the 2005 Ford Explorer (provided by Fordas OEM equipment). The Ford roll stability control system continuouslydetermines if the vehicle may be approaching a situation where rolloveris probable and applies braking to the wheels individually in an effortto prevent rollover. With the Ford system off and the system 32 of thethird embodiment turned off, the second test vehicle is expected toperform better than the first test vehicle (with the system off) and isexpected to have a higher rollover speed during a fish-hook maneuver,primarily due to the independent rear suspension. During initial testingwith the Ford system on and the system 32 of the third embodiment turnedoff, the second test vehicle still exhibited the tendency to roll(extreme tilting of the vehicle body) and allowed the center of gravity30 at the rear of the vehicle 22 to be raised significantly, and perhapsmore than having the Ford system turned off. Using the Ford system in afish-hook maneuver often caused the outside front tire to lock up andslide (constantly on some occasions and with a pulsing frequency onother occasions). This extreme braking on the outside front tire causedthe second test vehicle to slow rapidly, but it also caused the vehicleto dive and transfer much of the body weight to the front outside tire.In some tests, the front outside tire was deflecting extremely due tothe greater braking on that wheel by the Ford system and due to theweight shift. This shift of body weight to the right front tire caused alifting of the rear portion of the vehicle. The use of the Ford system(without the use of the system 32 of the third embodiment) did reducethe turning radius and reduce the risk of rollover, but mostly becausethe vehicle was slowed significantly by the extreme braking appliedautomatically by the Ford system. Hence, the tests with the Ford systemon were not under the same conditions of the prior fish-hook maneuvertests because the brakes were applied (as compared to the testsdiscussed regarding FIGS. 1A-4 and FIGS. 8A-11 where the brakes were notapplied).

The second test vehicle was also tested with the Ford system on and off,and with the system of the third embodiment of the present inventionturned on. In both cases, the system 32 of the third embodiment providedimprovements to handling and controllability of the vehicle, provided adecreased turning radius 90, provided a lowering of the vehicle's centerof gravity 30 (rather than raising), and significantly reduced the tiltof the vehicle body, as compared to not using the system 32 of thirdembodiment (with or without the use of the Ford system). The combinationof the computer-controlled braking of the Ford system and the control ofthe expansion of the rear springs 42 with the system 32 of the thirdembodiment provided the best test results. Thus again, an embodiment ofthe present invention still improves the handling and stability of thevehicle during a fish-hook maneuver test, even when the vehicle isequipped with an advanced braking control system.

FIGS. 14 and 15 show perspective views of the ratchet mechanism 52 forthe third illustrative embodiment. FIG. 16 is an enlarged side viewshowing a portion of the ratchet mechanism 52 of the third embodiment.The movable tongue system 46 is not shown in FIGS. 14 and 15, whichreveal a mounting plate 94 welded to the hollow member 72. This mountingplate 94 may be used to firmly attach the movable tongue system 46 tothe ratchet mechanism 52. A slot 96 is formed through the mounting plate94 and is aligned with the side hole 88 formed through a sidewall of thehollow member 72. This slot 96 allows the movable tongue member 54 ofthe third embodiment to extend into the hollow member 72 and engage theteeth 64 on the shaft member 71 (i.e., at the second tongue position62). In FIG. 14, the ratchet mechanism 52 is shown at a normal rideheight for the second test vehicle 22. In FIGS. 15 and 16, the ratchetmechanism 52 is shown fully extended, such extension being limited by astop pin 98. For the third embodiment, the shaft member 71 has a slot orgroove 100 formed along a side of the shaft member 71, as shown in FIG.16. The stop pin 98 extends through a side wall of the hollow member 72and slides within the groove 100 as the shaft member 71 moves in and outof the hollow member 72. In the third embodiment, the stop pin 98 is abolt with a rounded end. The groove 100 terminates before the end of theshaft member 71 and the pin 98 restricts the shaft member 71 from beingpulled completely out of the hollow member 72. Hence, when a vehicle 22is jacked up (e.g., when changing a tire or replacing brake pads) andthe suspension is permitted to expand, the shaft member 71 will not bepermitted to completely exit the hollow member 72.

As is also shown in FIGS. 14 and 15, the teeth 64 are formed along theshaft member 71 to correspond with an expected range of travel for thevehicle suspension during an extreme turning maneuver. Hence, the numberof teeth 64 and the placement of the teeth 64 along the shaft member 71may vary for different embodiments of the present invention.

FIGS. 17 and 18 are simplified views of ratchet mechanisms 52 (teeth andmovable tongue system not shown) to show two illustrative ways (amongmany others) to prevent the shaft member 71 from being pulled completelyout of the hollow member 72. The configuration shown in FIG. 17 isessentially the same as that of the third embodiment (FIGS. 14-16), inthat a stop pin 98 is fixed to the hollow member 72 and the groove 100is formed in the shaft member 71. FIG. 18 shows an oppositeconfiguration. In FIG. 18, a slot 100 is formed in, partially through orthrough, a sidewall of the hollow member 72 and a stop pin 98 extendsfrom the shaft member 71 and into (or through) the slot 100. Thus, inFIG. 18, the pin 98 moves with the shaft member 71 and the slot 100remains fixed relative to the hollow member 72. As will be apparent toone of ordinary skill in the art, there are many other ways (not shown)to prevent the shaft member 71 from being completely removed from thehollow member 72. Although preferred for most applications, anembodiment of the present invention may not include a way to prevent theshaft member 71 from being completely removed from the hollow member 72.

FIGS. 19A-19D show enlarged views of the teeth 64 on the shaft member 71moving relative to the tongue member 54 for the first embodiment(corresponding to FIG. 7) during a use of the system 32. In FIG. 19A,the tongue member 54 is being driven toward the second tongue position62 (as indicated by arrow 102) and is engaging the teeth 64 on the shaftmember 71. Also in FIG. 19A, the shaft member 71 is being moved upward(as indicated by the arrow 104) as the ratchet mechanism 52 is beingcompressed by the unsprung mass portion of the vehicle 22 moving towardthe sprung mass portion of the vehicle 22 (e.g., when the suspension onthat side being compressed by the body roll or tilt during a turn).FIGS. 19B and 19C show the motion of FIG. 19A continued. As the beveledside of a tooth 64 meets the tongue member 54, the tongue member 54 ispushed back toward the first tongue position 61, even though thesolenoid 48 is still exerting a force on the tongue member 54 to drivethe tongue member 54 toward the second tongue position 62 (as indicatedby arrow 102). Hence, the upward force exerted on the shaft member 71 bythe vehicle suspension being compressed is sufficient to overcome theforce of the solenoid 48. The solenoid 48 should be sized appropriatelyfor the system 32 to permit this motion to happen during use of thesystem 32. Preferably the solenoid 48 is sized so that the force of thesolenoid 48 is sufficient to hold the tongue member 54 in the secondtongue position 62 when needed (e.g., when the shaft member 71 moves theflat side of a tooth 64 toward the tongue member 54) but not so strongthat the tongue member 54 is bent or the teeth 64 are damaged when theshaft member 71 moves the beveled side of a tooth 64 toward the tonguemember 54 (as in FIGS. 19A-19C). When the system 32 is activated (as inFIGS. 7 and 19A-19D) and the spring of the suspension tries to expandthe suspension (push up on the vehicle body) (as indicated by arrow 106in FIG. 19D), the flat side of a tooth 64 engages with the tongue member54, as shown in FIG. 19D. This prevents further sliding of the shaftmember 71 in that direction 106, and thus prevents the suspension fromexpanding. Hence, FIGS. 19A-19D have illustrated the ratcheting effectprovided by the ratchet mechanism 52 and the movable tongue system 46for the first embodiment of FIGS. 5-7.

In the first, second, and third embodiments discussed above, oneparticular combination of a tongue member configuration and a toothconfiguration is shown, i.e., a rectangular-tipped tongue member 54 andteeth 64 beveled on one side (see e.g., FIGS. 6, 7, and 19A-19D).However, there are many possible teeth configurations and many possibletongue member configurations that may be used in an embodiment of thepresent invention. Next, some illustrative examples (among many othersnot shown) of different teeth configurations and different tongue memberconfigurations will be discussed with reference to FIGS. 20A-25.

FIGS. 20A-20D illustrate a set of teeth 64 and a tongue member 54 of afourth illustrative embodiment of the present invention. In FIGS.20A-20D, the teeth 64 have a curved side and a flat side, and the tonguemember 54 has a curved side and a flat side. FIGS. 20A-20D illustratefor the fourth embodiment the same motion of the shaft member 71relative to the tongue member 54 that was illustrated for the firstembodiment in FIGS. 19A-19D. Hence, the teeth 64 and tongue member 54 ofFIGS. 20A-20D provide another way to provide the ratchet effect for aratchet mechanism 52 of an embodiment.

FIGS. 21A-21D illustrate a set of teeth 64 and a tongue member 54 of afifth illustrative embodiment of the present invention. In FIGS.21A-21D, the teeth 64 have flat sides, and the tongue member 54 has abeveled side and a flat side. FIGS. 21A-21D illustrate for the fifthembodiment the same motion of the shaft member 71 relative to the tonguemember 54 that was illustrated for the first embodiment in FIGS.19A-19D. Hence, the teeth 64 and tongue member 54 of FIGS. 21A-21D showyet another way to provide the ratchet effect for a ratchet mechanism 52of an embodiment. Also, the fifth embodiment illustrates that the teeth64 may have a square or non-beveled pattern, while still providing aratcheting effect via the tongue member 54.

FIGS. 22A-22E show some illustrative examples (among many others notshown) for teeth patterns that may be implemented in an embodiment ofthe present invention. These teeth 64 shown in FIGS. 22A-22E are shownformed on shaft members 71, but may be formed on other components orportions of an embodiment. It should be noted that although each tooth64 of each corresponding set of teeth 64 is the same for theillustrative embodiments shown and described herein thus far, the teeth64 in a given set of teeth for an embodiment may not all be the same andmay not all be uniformed spaced and/or uniformly distributed relative toeach other. For example, the spacing between teeth 64 of a given set ofteeth may vary at different locations along the shaft member 71. Asanother example (not shown), teeth 64 at the ends of a given set ofteeth may differ from other teeth in the set. Also, a set of teeth 64for an embodiment may have any number of teeth (e.g., 1, 2, 3, 4, 10,14, 31, etc.).

FIGS. 23A-23E show some illustrative examples (among many others notshown) for cross-sections of tongue members 54 that may be implementedin an embodiment of the present invention. Hence, the tongue member 54of an embodiment may have any suitable or desirable shape. Thecross-section of the tongue member 54 may be uniform along the extent ofthe tongue member 54, or it may vary and differ at different locationsalong the extent of the tongue member 54.

FIGS. 24A-24Q are side views showing ends of tongue members 54 (i.e.,the end that engages the teeth 64 of a ratchet mechanism 52). FIGS.24A-24Q show some illustrative examples (among many others not shown)for end profiles of tongue members 54 that may be implemented in anembodiment of the present invention. Hence, the end profile of a tonguemember 54 for an embodiment may have any suitable or desirable shape.Typically, the end profile shape will correspond to or be adapted to atleast partially mate with a recess profile between teeth 64 and/or anyother portion of one or more teeth 64.

FIG. 25 illustrates a set of teeth 64 and a tongue member 54 of a sixthillustrative embodiment of the present invention. Only part of thesystem 32 of the sixth embodiment is shown, for purposes of simplifyingthe drawing. In FIG. 25, the tongue member 54 is larger and has multipleteeth 108, rather than just one “tooth” (i.e., the end of the tonguemember 54). FIG. 25 illustrates that the tongue member 54 may be largerand that the tongue member 54 may have one or more teeth 108 formedtherein or formed thereon. It is further contemplated that in anembodiment (not shown) of the present invention the tongue member 54 mayhave a series of teeth 108 (as in FIG. 25, or more) and the shaft member71 may have only one tooth 64 or pin or tongue extending therefromadapted to engage with the teeth 108 on the tongue member 54 to providea ratcheting effect when engaged.

FIG. 26 is a side view showing part of a seventh embodiment of thepresent invention. In the seventh embodiment, the ratchet mechanism 52is integrated with a shock absorber 40 (dampener). Thus, instead ofhaving the ratchet mechanism 52 mounted separately from the shockabsorber 40 (as in the first in embodiment shown in FIG. 5), a shockabsorber 40 may be replaced by a ratchet mechanism 52 of the seventhembodiment. When the system 32 is on but not activated (i.e., solenoid48 is not driving tongue member 54 toward second tongue position 62) forthe seventh embodiment, the ratchet mechanism 52 merely acts as a shockabsorber. The shock absorber 40 acts as a shaft member 71. A set ofteeth 64 may be attached to or integrally formed on a first portion 111of the shock absorber 40, as shown in FIG. 26 for example. A secondportion 112 of the shock absorber 40 is slidably coupled to the firstportion 111 of the shock absorber 40. The second portion 112 of theshock absorber 40 is attached to or is an integral part of the hollowmember 72. In FIG. 26, a sidewall portion of the hollow member 72 isbroken away to illustrate the portions of the system 32 otherwise hiddenby the hollow member 72. Also, a cover 50 of the movable tongue system46 is broken away in FIG. 26 to show portions of the movable tonguesystem 46 that would be otherwise hidden. One of the advantages of theseventh embodiment is that it may save space by combining the shockabsorber 40 with the ratchet mechanism 52 of the system 32. Anotheradvantage of the seventh embodiment is that the system 32 may beinstalled quickly and easily on a vehicle 22 by simply replacing anexisting shock absorber 40 with the ratchet mechanism 52 of the system32, rather than having to install separate brackets for the mounting theratchet mechanism 52.

Although the embodiments described thus far have slider mechanisms withteeth 64 extending along a straight line, the ratchet mechanism 52 maybe configured differently for other embodiments. FIGS. 27-29 and 39 showsome illustrative embodiments (among many others not shown) that havedifferent types of ratchet mechanisms 52, and different installationpositions in relation to the suspension system of the vehicle 22.

FIG. 27 shows a system 32 of an eighth embodiment of the presentinvention operably installed on a vehicle 22. In FIG. 27, a rearindependent suspension system for one side of the vehicle 22 is shown.The wheel and tire are removed in FIG. 27. Also, an outline for thebrake disc 114 of the disc brake system is shown in dashed line and thebrake disc 114 is shown transparently to illustrate the componentslocated behind the brake disc 114. The brake caliper 116 is shown. Thesuspension system has a coil spring 42, a shock absorber 40, an uppercontrol arm 118, a wheel axle 120 (with wheel studs 122 extendingtherefrom), an upright member 124, and a lower control arm 126, as shownin FIG. 27. In the eighth embodiment shown in FIG. 27, the ratchetmechanism 52 of the vehicle stability control system 32 is attachedbetween a sprung mass portion (e.g., frame or body) of the vehicle 22and the upper control arm 118 of the suspension (which is part of theunsprung portion of the vehicle 22). In other variations of the eighthembodiment, the ratchet mechanism 52 may be attached to other portionsof the suspension, including (but not necessarily limited to): a lowercontrol arm 126, an upright member 118, or a bracket extending from amovable part of the suspension system.

The ratchet mechanism 52 of FIG. 27 includes two arms 131, 132 that arepivotably coupled together at a first pivot point 134. Hence, the firstarm 131 can pivot at the first pivot point 134 relative to the secondarm 132. The first arm 131 is pivotably coupled to the upper control arm118. The second arm 132 is pivotably coupled to a sprung mass portion(e.g., frame or body) of the vehicle 22. A tooth arm 138 is attached to(or may be an integral part of) the first arm 131, and the tooth arm 138extends from the first arm 131 and across the second arm 132, as shownin FIG. 27. The tooth arm 138 extends across at least part of a movabletongue system 46. The movable tongue system 46 of the eighth embodimentis attached to the second arm 132. As shown in FIG. 27, the tooth arm138 may extend through the movable tongue system 46. The tooth arm 138has a set of ratchet teeth 64 attached thereto or formed thereon. Themovable tongue system 46 of the eighth embodiment includes a solenoid 48and a tongue member 54, similar to that of the first embodiment. Thesolenoid 48 drives the tongue member 54 into engagement with the ratchetteeth 64 on the tooth arm 138 to provide a ratchet effect for theratchet mechanism 52 when the system 32 is activated. When the system 32of the eighth embodiment is activated, the vehicle wheel is permitted tomove toward the vehicle body (compressing the coil spring 42), but thewheel is prevented from moving away from the vehicle body (preventingthe coil spring 42 from pushing the vehicle body upward). When thesystem 32 of the eighth embodiment is not activated, the tooth arm 138is free to move in both directions relative to the second arm 132.

FIG. 28 shows a system 32 of a ninth embodiment of the present inventionoperably installed on a vehicle 22. As in FIG. 27, FIG. 28 shows a rearindependent suspension system for one side of the vehicle 22. The wheeland tire are removed in FIG. 28. Also, an outline for the brake disc 114of the disc brake system is shown in dashed line and the brake disc 114is shown transparently to illustrate the components located behind thebrake disc 114. The brake caliper 116 is shown. The suspension systemhas a coil spring 42, a shock absorber 40, an upper control arm 118, awheel axle 120 (with wheel studs 122 extending therefrom), an uprightmember 124, and a lower control arm 126, as shown in FIG. 28. In theninth embodiment shown in FIG. 28, the ratchet mechanism 52 of thevehicle stability control system 32 is attached between a sprung massportion (e.g., frame or body) of the vehicle 22 and the upper controlarm 118 of the suspension (which is part of the unsprung portion of thevehicle 22). In other variations of the ninth embodiment, the ratchetmechanism 52 may be attached to other portions of the suspension,including (but not necessarily limited to): a lower control arm 126, anupright member 124, or a bracket extending from a movable part of thesuspension system.

The ratchet mechanism 52 of FIG. 28 includes a suspension arm 140 and aratchet gear 142. A first end 144 of the arm 140 is pivotably coupled toa sprung mass portion (e.g., frame or body) of the vehicle 22. A secondend 146 of the arm 140 is pivotably coupled to the upper control arm 118of the suspension. The ratchet gear 142 extends from the arm 140 about apivot axis 148 of the first end 144. In the ninth embodiment, theratchet gear 142 extends circumferentially completely around the pivotaxis 148. In other embodiments (not shown), however, the ratchet gear142 may only extend (circumferentially) partially around the pivot axis148. In the ninth embodiment, the ratchet gear 142 is fixed relative tothe arm 140 and pivots with the arm 140. The ratchet gear 142 has aseries of ratchet teeth 64. The teeth 64 of a ratchet gear 142 may haveany suitable shape, but preferably corresponds to a shape chosen for themovable tongue member 54. The movable tongue system 46 of the ninthembodiment may be similar to that of the first embodiment (describedabove), for example. The movable tongue system 46 of the ninthembodiment is fixed relative to the sprung mass portion. When the system32 of the ninth embodiment is activated, the vehicle wheel is permittedto move toward the vehicle body (compressing the coil spring), but thewheel is prevented from moving away from the vehicle body (preventingthe coil spring 42 from pushing the vehicle body upward). When thesystem 32 of the ninth embodiment is not activated, the ratchet gear 142is free to pivot in both rotational directions relative to the tonguemember 54 and the tongue member 54 does not engage the teeth 64.

FIG. 29 shows a system of a tenth embodiment of the present inventionoperably installed on a vehicle. As in FIGS. 27 and 28, FIG. 29 shows arear independent suspension system for one side of the vehicle, exceptthat FIG. 29 shows a different view of the suspension. The wheel andtire are removed in FIG. 29. The brake system shown in FIG. 29 includesa brake caliper (not shown) and a brake disc 114. The suspension systemhas a coil spring 42, a shock absorber 40, an upper control arm 118, awheel axle 120 (with wheel studs 122 extending therefrom), an uprightmember 124, and a lower control arm 126, as shown in FIG. 29. In thetenth embodiment shown in FIG. 29, the ratchet mechanism 52 of thevehicle stability control system 32 is attached between a sprung massportion (e.g., frame or body) of the vehicle 22 and the upper controlarm 118 of the suspension (which is part of the unsprung portion of thevehicle). Also, the ratchet mechanism 52 of the tenth embodiment is anintegral part of the suspension system. The upper control arm 118 of thesuspension system is part of the ratchet mechanism 52 in the tenthembodiment, as shown in FIG. 29. In other variations (not shown) of thetenth embodiment, the lower control arm 126 or some other suspensioncomponent that pivotably connects between the sprung mass portion andthe unsprung mass portion (e.g., Packard arm, trailing arm, anti-swaybar) may be part of the ratchet mechanism 52. Furthermore, anysuspension component that pivots when the sprung mass portion movestoward and away from the unsprung mass portion of the vehicle 22 may bepart of the ratchet mechanism 52 in other embodiments, so long as therestriction of pivoting of the suspension component relative to anothercomponent (sprung or unsprung) will also restrict the spring 42 of thesuspension from expanding via the ratchet mechanism 52 formed there.

The ratchet mechanism 52 of FIG. 29 includes a suspension arm (uppercontrol arm 118) and a ratchet gear 142. A first end 144 of the arm 118is pivotably coupled to a sprung mass portion (e.g., frame or body) ofthe vehicle 22. A second end 146 of the arm 118 is pivotably coupled tothe upright member 124 of the suspension. The ratchet gear 142 extendsfrom the suspension arm 118 about a pivot axis 148 of the first end. Inthe tenth embodiment, the ratchet gear 142 extends circumferentiallycompletely around the pivot axis 148. In other embodiments (not shown),however, the ratchet gear 142 may only extend (circumferentially)partially around the pivot axis 148. In the tenth embodiment, theratchet gear 142 is fixed relative to the suspension arm 118 and pivotswith the arm 118. The ratchet gear 142 has a series of ratchet teeth 64.The teeth 64 of a ratchet gear 142 may have any suitable shape, butpreferably corresponds to a shape chosen for the movable tongue member54. The movable tongue system 46 of the tenth embodiment may be similarto that of the first embodiment (described above), for example. Themovable tongue system 46 of the ninth embodiment is fixed relative tothe sprung mass portion. When the system 32 of the tenth embodiment isactivated, the vehicle wheel (not shown) is permitted to move toward thevehicle body (compressing the coil spring 42), but the wheel isprevented from moving away from the vehicle body (preventing the coilspring 42 from pushing the vehicle body upward). When the system 32 ofthe tenth embodiment is not activated, the ratchet gear 142 is free topivot in both rotational directions relative to the tongue member 54 andthe tongue member 54 does not engage the teeth 64.

FIG. 30 is a side view of a slider mechanism 152 and movable tonguesystem 46 of an eleventh embodiment of the present invention. Theeleventh embodiment is the same as the first embodiment (see e.g., FIGS.6 and 7), except that the teeth 64 on the shaft member 71 are different.However, due to the different shape of the teeth 64 (in combination withthe chosen shape of the tongue member 54), the slider mechanism 152 ofthe eleventh embodiment is not a ratchet mechanism. The eleventhembodiment merely locks the position of the suspension when activated,rather than allowing further compression of the suspension (as the firstembodiment allows). The first embodiment of FIGS. 5-7 has been found toperform better than the eleventh embodiment during testing on the firsttest vehicle 22 performing fish-hook maneuvers. Thus, the firstembodiment and other embodiments that provide a ratchet mechanism 52(rather than fully locking the position of the suspension) may be morepreferred for most applications.

As mentioned above, a preferred embodiment of the present inventionpreferably includes a signal generating device 154, a triggering device156, a movable tongue system 46, and a ratchet mechanism 52. This isillustrated generally and schematically at a high level by FIG. 31. Muchdetail has been provided above regarding some illustrative examples ofsome possible variations for the ratchet mechanism 52 and the tonguemember 54. Next, illustrative examples of some possible variations forthe signal generating device 154, triggering device 156, and movabletongue system 46 will be discussed. For each device there also may bevariations among the components and combination of possible componentsthat make up the device.

Referring again to the first embodiment of FIGS. 5-7, the signalgenerating device 154, triggering device 156, and movable tongue system46 of the first embodiment will be described with reference to FIGS.32-35. As mentioned above, the signal generating device 154 of the firstembodiment is an acceleration measuring device. FIG. 32 is a simplifiedschematic illustrating the connection and/or communication between theacceleration measuring device 154, the triggering device 156, and themovable tongue system 46. FIG. 33 is a simplified schematic illustratingthe major components of the movable tongue system 46 of FIG. 32, whichinclude an electro-mechanical actuator 48 and a movable tongue member54. The electro-mechanical actuator 48 drives or moves the tongue member54 from a first tongue position 61 to or toward a second tongue position62 (see e.g., FIGS. 6 and 7 illustrating first and second tonguepositions 61, 62 for the first embodiment).

In the first embodiment, the electro-mechanical actuator 48 is asolenoid. In a prototype of the first embodiment, a Ledex brand Size 5SFsolenoid is used on each side of the system 32, for example. Thespecifications for this linear solenoid (part number 129450-0XX) areprovided in Table 1 below. Some of the advantages of using a solenoidmay include: little or no maintenance required; fast reaction time foractivation; fast movement for driving tongue member; small size; onlyrequires electrical energy source; and low cost, for example. In otherembodiments (not shown), however, the electro-mechanical actuator 48used to move the tongue member 54 may be any of a wide variety ofsuitable components, systems, or combinations of components, including(but not limited to): an electric motor, a solenoid, anelectrically-switchable hydraulic valve, a hydraulic actuator, anelectrically-switchable pneumatic valve, a pneumatic actuator, anelectrically-switchable vacuum valve, a vacuum-driven actuator, anelectrically-switchable pyrotechnic-driven actuator, anelectrically-switchable explosive-charged actuator, anelectrically-switchable compressed-gas-driven actuator, and combinationsthereof, for example. TABLE 1 Example Solenoid Specifications DielectricStrength 23 awg. 1000 VRMS; 24-33 awg. 1200 VRMS Coil Resistance 23-33awg. ± 5% Weight 9.0 oz. (255 grams) Holding Force 58.0 lbs. (258.0 N) @105° C. Dimensions 1.875 in. × 0.880 in.

In the first embodiment, the acceleration measuring device 154 is asemiconductor chip having an accelerometer sensor. One example of anaccelerometer is an Analog Devices brand dual-axis accelerometer on asingle integrated circuit chip with signal conditioned voltage outputs(model number ADXL311). This accelerometer has a full-scale range of ±2g, and can measure both static and dynamic accelerations. Advantages ofthis accelerometer may include being: low cost, small size, highreliability, and light weight, for example. The outputs are analogvoltages proportional to acceleration. However, only a single axisaccelerometer is needed for most applications of the present invention.In other embodiments, other makes, models, and types of accelerometersmay be used. A lookup table may be used to translate the output voltageto the corresponding acceleration measurement along a given axis. Anaccelerometer and the other electrical components of the system 32 maybe mounted together or separately at any suitable location on a vehicle22. It is contemplated that the signal generating device 154 and atleast part of the triggering device 156 may be part of a same integratedcircuit chip.

The triggering device 156 of the first embodiment is a microcontrolleror microprocessor on a single integrated circuit chip. Themicroprocessor 156 may be programmed (e.g., running software code storedtherein, or having the code temporarily or permanently burned in) toevaluate the output signal from the signal generating device 154. Forexample, a Microchip brand enhanced flash microcontroller (PIC16F87XA)may be used, which includes: a 10-bit, up to 8 channelsanalog-to-digital converter; an analog comparator module; programmableon-hip voltage reference module; programmable input multiplexing fromdevice inputs and internal voltage reference; comparator outputs thatare externally accessible; enhanced flash program memory; data EEPROMmemory; fully static design; operating voltage of 2.0V to 5.5V;commercial and industrial temperature ranges; and low power consumption.In other embodiments (not shown), however, other microprocessors orother controllers may be used (analog or digital or combination analogand digital) as a triggering device 156. Also, in other embodiments (notshown), a purely analog electrical circuit may be used to evaluatewhether the output signal from a signal generating device 154 exceedssome predetermined threshold level. For example, the triggering device156 may include an analog electrical circuit of one or more capacitors,one or more resistors, and one or more transistors, to providecomparators and amplifiers (see e.g., general schematic of FIG. 36). Itis also contemplated that at least part of the signal generating device154 and/or at least part of the triggering device 156 may be an integralpart of or within the same casing as at least part of the movable tonguesystem 46, and vice versa.

FIG. 34 is a simplified schematic showing components of the firstembodiment (the signal generating device 154, the triggering device 156,and part of the movable tongue system 46). FIG. 35 is a detailedelectrical schematic for the components of FIG. 34, for the firstembodiment. This is merely one example among many ways to provide thesefunctions. The vehicle stability control system 32 of the firstembodiment is a prototype system used for testing and developing thesystem 32. Thus, the triggering device 156 of the first embodiment isadjustable and an LED display 158 is provided (see FIG. 35) for seeingsettings made to the set points and to see output data stored in themicrocontroller. In other embodiments, such as a production version ofthe system 32 for an OEM system, the circuitry and devices may be muchmore simplified because the threshold limits and the logic may be setwithout needing future adjustments. Furthermore, it is contemplated thatthe vehicle's CPU or ECU may be used to run a simple algorithm todetermine if the system 32 needs to be activated based on an output froma signal generating device 154. Thus, the triggering device 156 may bepart of the vehicle's other systems.

In the first embodiment, for example, output signals from theaccelerometer 154 are provided as inputs to the microprocessor. Withinthe microcontroller chip (in this case), the analog signal from theaccelerometer 154 is converted to a digital signal. This digital signalis then compared to a threshold value to determine whether the outputsignal from the accelerometer exceeds the threshold level for somepredetermined number of cycles (one or more). When the output signalfrom the accelerometer does exceed the predetermined threshold level,the output signal from the microprocessor goes high and that outputsignal is then amplified by one or more amplifiers. The amplifiers maybe a series of transistors to provide the voltage and ampere levelsrequired to drive the solenoids, for example. In the first embodiment,both left and right solenoids 48 are activated at the same time. Inother embodiments, the left and right sides may be activated atdifferent times in accordance with any set of criteria or conditionsprogrammed into the system. The system 32 may be activated for somepredetermined amount of time to keep the solenoids 48 energized anddriving the tongue member 54 toward the second tongue position 62. Thispredetermined amount of time may be adjustable or preset in the system32. Preferably, the system 32 remains activated until the vehiclebecomes stable. The system 32 may be kept activated based uponmeasurements taken from any of a variety of sensors and/or types ofsensors that can provide measurement(s) (singularly or when combinedsignals are processed) indicating that the vehicle 22 is stable (e.g.,not experiencing lateral accelerations above some level, speed reducedbelow some level, tilt angle of the vehicle below some level for someperiod of time, etc.). In a preferred embodiment, the system is set tobe very sensitive (e.g., very low lateral acceleration threshold foractivating the system, such as about 0.2 g for example) to activatepreemptively before there is any significant movement of the vehicletoward a rollover. This is in contrast to all or most all other rollcontrol systems that are only activated after the vehicle reaches acritical and advanced stage of rolling over. To use such a sensitivesetting for the lateral acceleration level of activation, it ispreferred to have the system on standby (e.g., off, or on but notallowing solenoid to be activated) at lower speeds (e.g., below about 30mph). Otherwise the system would likely come on while turning normalcity comers or sharp comers at low speeds and entering driveways, forexample. This would be unneeded and probably undesirable. At low speeds(e.g., below 30 mph), the driver would likely hear and feel the systembeing activated and deactivated. But at higher speeds (e.g., above 30mph), the system would seldom, if ever, be activated, and the driverwould probably not hear or notice the system being activated anddeactivated due to the higher speed and road noise.

Although the illustrative embodiments discussed above may have the sametype of signal generating device 154, triggering device 156, and movabletongue system 46 as the first embodiment, and may have the same type oflogic for triggering and activating the system 32, other embodiments andvariations of embodiments may have different types and combinations ofcomponents and logic for the signal generating device(s) 154, triggeringdevice(s) 156, and movable tongue system(s) 46.

For an embodiment of the present invention, a vehicle velocity or speedsignal may be input to the microprocessor in addition to theacceleration measurement(s). In such case, the system 32 may beprogrammed so that the system 32 will not be activated unless thevehicle's speed is above a predetermined speed threshold level (e.g., 30mph). This may be more practical and preferred for several reasons. Whenmaking a sharp turn at low speeds (e.g., during normal driving), thelateral acceleration may be much higher while not putting the vehicle 22in a dangerous maneuver (due to the low speed). Also, most vehicles arenot susceptible to rollovers (without being tripped) at speeds below 30mph, for example, and thus the system may not be needed at such speeds.The speed signal may be generated by a separate speed sensor (used onlyfor this system 32) and/or may be provided by an existing sensor of dataoutput given by a vehicle's other systems (e.g., speed signal sent tocruise control system from vehicle CPU).

In another embodiment of the present invention, the signal generatingdevice 154 may include (singularly or in any combination) other types ofdevices and/or sensors, including (but not limited to): a sensor formeasuring movement (acceleration, velocity, and/or position) of avehicle's steering wheel; a sensor for measuring and providing an outputsignal for a vehicle body position relative to a ground surface; asensor for measuring and providing an output signal for a vehicle body'stilt angle relative to a ground surface; a sensor for measuring andproviding an output signal for a vehicle body position relative to atleast one vehicle wheel; or a sensor for measuring and providing anoutput signal for a tilt angle of a vehicle body relative to one or morevehicle wheels, for example. The system 32 may be programmed or hardwired to be triggered based on any number of input signals from anynumber of signal generating devices 154, which may provide multipleand/or confirming indications that a vehicle 22 is performing a maneuverthat may lead to rollover conditions (e.g., hard corning, suddensteering movements at high speeds, etc.). With the benefit of thisdisclosure, one of ordinary skill in the art will likely realize manypossible ways to evaluate conditions of a vehicle's dynamics todetermine whether a ratchet mechanism should be engaged by a tonguemember to provide the ratcheting effect desired to enhance the stabilityand control of a vehicle using an embodiment of the present invention.The illustrative signal generating devices 154 and triggering devices156 disclosed herein are merely examples and in no way limit what othersmay be implemented into an embodiment of a present invention. Oftensignals needed or desired for an embodiment may be generated already byan existing component of the vehicle, and thus some existing part of thevehicle may be used as the signal generating device or as part of thesignal generating device for the system.

FIGS. 37A-37C illustrate a shaft member 71 with a single tooth 64 and atongue member 54 of a twelfth illustrative embodiment of the presentinvention. Only part of the system 32 of the twelfth embodiment isshown, for purposes of simplifying the drawing. FIGS. 37A-37C alsoillustrate the movement of the shaft member 71 relative to the tonguemember 54 for the twelfth embodiment. Thus, the twelfth embodiment is anexample of one way (among many others possible) to provide a ratchetmechanism 52 where the shaft member 71 has only one tooth 64.

FIG. 38 illustrates a shaft member 71 with a single tooth 64 and atongue member 54 of a thirteenth illustrative embodiment of the presentinvention. Only part of the system 32 of the thirteenth embodiment isshown, for purposes of simplifying the drawing. FIG. 38 also illustratesthe tongue member 54 for the thirteenth embodiment in the second tongueposition 62. Thus, the thirteenth embodiment is an example of one way(among many others possible) to provide a ratchet mechanism 52 where theshaft member 71 has only one tooth 64 formed by one recessed portion 76.

FIG. 39 shows a system 32 of a fourteenth illustrative embodiment of thepresent invention operably installed on a vehicle 22. As in FIG. 29,FIG. 39 shows a rear independent suspension system for one side of thevehicle 22. The wheel and tire are removed in FIG. 39. The brake systemshown in FIG. 39 includes a brake caliper (not shown) and a brake disc114. The suspension system has a coil spring 42, a shock absorber 40, anupper control arm 118, a wheel axle 120 (with wheel studs 122 extendingtherefrom), an upright member 124, and a lower control arm 126, as shownin FIG. 39. In the fourteenth embodiment shown in FIG. 39, the ratchetmechanism 52 of the vehicle stability control system 32 is attachedbetween a sprung mass portion (e.g., frame or body) of the vehicle 22and the lower control arm 126 of the suspension (which is part of theunsprung portion of the vehicle). In other variations of the fourteenthembodiment, the ratchet mechanism may be attached to other unsprungportions of the vehicle 22 (e.g., upper control arm 118, upright member124).

The ratchet mechanism 52 of FIG. 29 includes a pulley member 170, aratchet gear 142, and a cable 172. The pulley member 170 is rotatablycoupled to the sprung mass portion of the vehicle 22 (e.g., frame 34).The cable 172 has a first end 174 attached to the pulley member 170. Thecable extends from the pulley member 170 and is attached to the lowercontrol arm 126 at a second end 176 of the cable 172. The pulley member170 is adapted to spool the cable 172 at least partially around thepulley member 170 as the pulley member pivots or rotates. A pulleyspring (not shown) biases the pulley member 170 to pivot in a directionthat will spool the cable 172 onto the pulley member 170 to keep tensionon the cable 172. A ratchet gear 142 extends from the pulley member 170.In the fourteenth embodiment, the ratchet gear 142 extendscircumferentially completely around a pivot axis 148 of the pulleymember 170. In other embodiments (not shown), however, the ratchet gear142 may only extend (circumferentially) partially around the pivot axis148. In the fourteenth embodiment, the ratchet gear 142 is fixedrelative to the pulley member 170 and pivots with it. The ratchet gear142 has a series of ratchet teeth 64. The teeth 64 of a ratchet gear 142may have any suitable shape, but preferably correspond to a shape chosenfor the movable tongue member 54. The movable tongue member 54 of thetwelfth embodiment has a pawl shape. The tongue member 54 of the twelfthembodiment is adapted to pivot from a first tongue position to or towarda second tongue position 62 (second tongue position 62 is shown in FIG.39). Thus, the twelfth embodiment illustrates that the tongue member 54may be moved in a pivotal or rotational movement when moving from afirst tongue position to or toward a second tongue position for anembodiment of the present invention.

It is also contemplated that an embodiment of the present invention mayuse a one way bearing that can be engaged and disengaged (e.g., along aspline shaft) to provide a ratchet mechanism. With the benefit of thisdisclosure one of ordinary skill in the art may realize other possibleways to provide a ratchet mechanism for an embodiment of the presentinvention.

Although initial testing has shown that a system 32 of the presentinvention works well when only installed on a rear suspension of avehicle 22 (especially for SUVs), it is contemplated that an embodimentof the present invention may be installed on the front and rearsuspensions of a vehicle, or only on a front suspension of a vehicle. Itis further contemplated that a portion of an embodiment installed on afront suspension of the vehicle may be triggered and operated togetherwith, partially independent of, or completely independent of anembodiment installed on a rear suspension of the same vehicle.

Many advantages and safety benefits may be provided by installing andusing a vehicle stability control system 32 on a vehicle 22, inaccordance with an embodiment of the present invention. Life threateningsituations may be detected and dealt with in a simple but effectivemanner. An embodiment of the present invention may provide a proactiveway to give a driver more control well before the vehicle reaches acompromised rollover position. Tests have shown that a vehicle may becapable of making a much sharper turn when the system 32 is activated.During an extreme or emergency maneuver, sometimes a few feet or moredecrease in turning radius may make the difference between a deadlycollision and a minor scrape. A system 32 of an embodiment may bechanged from a completely inactive (non-interfering) state to apartially or completely activated state in milliseconds. A system 32 ofan embodiment may be installed as an aftermarket item on existingvehicles, it may be provided as an upgrade option for new vehicles(e.g., installed at the dealer), and it may be an integral part of a newvehicle (e.g., OEM equipment, standard equipment).

It is recognized that a large percentage (perhaps 90% or more) ofrollovers are caused by trips (hitting an object while cornering orsliding sideways). Trip objects may be curbs, embankments, pot holes,uneven pavement, and other obstructions that interfere with the vehiclemoving laterally (e.g., rapid transition from sliding on ice to non-icedpavement), for example. Many of these accidents are caused by a driverlosing control of the vehicle when the vehicle is unable to make a smallradius turn at high speeds to avoid such trip objects. Use of anembodiment of the present invention may significantly increase thestability of a vehicle and allow it to make smaller radius turns,thereby possibly avoiding the trip object. Also, because the suspensionis still permitted to be compressed by the ratchet mechanism of anembodiment, the wheel may be able to move over or climb over the tripobject, rather than stopping at the trip object. Furthermore, by keepingthe vehicle's center of gravity 30 lower when the system 32 isactivated, the lateral force required to roll upon hitting a trip objectmay be greatly increased, and such increased lateral force may not bereached (e.g., trip object broken or part of vehicle hitting trip objectbroken to absorb part of the lateral force energy and vehicle momentum).

Tire blowouts and tire debeading have been caused by major weight shiftsto the outside front tire in a severe turn. When a tire blows out ordebeads during a severe turn, the wheel rim hitting the ground anddigging into the ground may provide a trip mechanism. Many vehiclerollovers have been caused by tire blowouts and tire debeading. Byreducing the lateral weight shift and weight transfer of the vehicle'sbody weight when a system 32 of an embodiment is activated, the weightand pressure exerted on outer tires is reduced. The problems of tireblowouts or tires debeading during severe cornering may be reduced oreliminated through the use of an embodiment of the present invention dueto the reduced forces exerted on the outside tires.

Other advantages of some embodiments of the present invention mayinclude (but are not necessarily limited to): requiring little or nomaintenance during the life of the system; the system requires noadjusting; the system is silent or very quiet when activated; the systemmay be activated and fully engaged in less than 10 ms, and possibly asfast as 4 ms; the system may be used without affecting steering,braking, throttle position, and other stability control systems alreadypresent on a vehicle during normal driving; the system may be used inconjunction with other vehicle stability control systems to provide acumulative improvement in stability and control; use of an embodimentmay enable the use of a softer and more comfortable suspension setupwithout sacrificing safety; in a preferred embodiment, the system is offat speeds below about 30 mph and comes on standby at speeds over 30 mph,but remains inactive until needed; the system becomes fully operationalin less than 1/100 of a second; the system requires no action ordecision on the part of the driver; the system turns itself off when nolonger needed and the vehicle returns to the same state as before thesystem was turned on (no permanent change in activating the system);when activated, the system may stabilize the vehicle in a severe turn togive the driver much more maneuverability and control of the vehicle;may be installed on any vehicle, regardless of vehicle size or type(e.g., buses, large trucks, vans, SUVs, station wagons, cars); thesystem may be installed with little or no permanent alterations to thevehicle; the system is inexpensive; the system is reliable; and thesystem may be used many times and/or repeatedly without maintenance,rebuilding, or repair.

Use of an embodiment of the present invention may allow many, if notall, existing SUVs and pickup trucks to improve their safety ratingswith agencies, such as NHTSA. But more importantly, use of an embodimentof the present invention may save thousands of lives and preventthousands of serious accidents (e.g., rollovers) and injuries. Suchreductions not only benefit society greatly, but also may reduce orreverse the rising cost of insurance coverage.

Although embodiments of the present invention and at least some of itsadvantages have been described in detail, it should be understood thatvarious changes, substitutions, and alterations can be made hereinwithout departing from the spirit and scope of the invention as definedby the appended claims. Moreover, the scope of the present applicationis not intended to be limited to the particular embodiments of theprocess, machine, manufacture, composition of matter, means, methods,and steps described in the specification. As one of ordinary skill inthe art will readily appreciate from the disclosure of the presentinvention, processes, machines, manufacture, compositions of matter,means, methods, or steps, presently existing or later to be developed,that perform substantially the same function or achieve substantiallythe same result as the corresponding embodiments described herein may beutilized according to the present invention. Accordingly, the appendedclaims are intended to include within their scope such processes,machines, manufacture, compositions of matter, means, methods, or steps.

1. A method of limiting a movement of a sprung mass portion of a vehiclerelative to an unsprung mass portion of the vehicle, the methodcomprising: moving a tongue member of a vehicle stability control systemfrom a first tongue position toward a second tongue position; engaging atooth of a ratchet mechanism with the tongue member, the ratchetmechanism being part of the vehicle stability control system, and theratchet mechanism being mechanically coupled to the unsprung massportion and to the sprung mass portion of the vehicle; and when thetongue member engages the tooth, restricting a movement of the unsprungmass portion away from the sprung mass portion, wherein the tonguemember does not restrict the movement of the unsprung mass portionrelative to the sprung mass portion when the tongue member is in thefirst tongue position.
 2. A method of limiting expansion of a springmember on a vehicle, wherein the spring member is biased between asprung mass portion of the vehicle and an unsprung mass portion of thevehicle, the method comprising: moving a tongue member from a firsttongue position toward a second tongue position; engaging a set ofratchet teeth with the tongue member as the tongue member is movedtoward a second tongue position, wherein the ratchet teeth are part of aratchet mechanism, the ratchet mechanism being mechanically coupled tothe sprung mass portion and to the unsprung mass portion of the vehicle;and restricting a movement of the unsprung mass portion away from thesprung mass portion when the tongue member is moved toward the secondtongue position and into the set of ratchet teeth.
 3. The method ofclaim 2, wherein the moving of the tongue member from the first tongueposition toward the second tongue position is performed after stepscomprising: receiving an output signal from a signal generating device;determining whether the output signal meets or exceeds a predeterminedthreshold level; and if the output signal meets or exceeds thepredetermined threshold level, activating an electro-mechanicalactuator, wherein the electro-mechanical actuator is used for the movingof the tongue member.
 4. The method of claim 3, wherein the signalgenerating device is an accelerometer, and wherein the method furthercomprises measuring a lateral acceleration of the vehicle with theaccelerometer, wherein the output signal corresponds to the lateralacceleration of the vehicle.
 5. The method of claim 4, wherein themethod further comprises measuring a velocity of the vehicle with asensor, wherein the activating of the electro-mechanical actuator isonly performed if the velocity is above a predetermined velocity level.6. The method of claim 3, wherein the method further comprises measuringa movement of a steering wheel on the vehicle with a sensor, wherein theoutput signal corresponds to the movement of the steering wheel as afunction of time.
 7. The method of claim 6, wherein the method furthercomprises measuring a velocity of the vehicle with a sensor, wherein theoutput signal corresponds to the movement of the steering wheel as afunction of time.
 8. The method of claim 3, wherein the method furthercomprises measuring a tilt angle of a body of the vehicle relative to aground surface with one or more sensors, wherein the output signalcorresponds to the tilt angle of the vehicle.
 9. The method of claim 3,wherein the method further comprises measuring a tilt angle of a body ofthe vehicle relative to one or more vehicle wheels with one or moresensors, wherein the output signal corresponds to the tilt angle of thevehicle.
 10. The method of claim 3, wherein the electro-mechanicalactuator comprises a component selected from the group consisting of anelectric motor, a solenoid, an electrically-switchable hydraulic valve,a hydraulic actuator, an electrically-switchable pneumatic valve, apneumatic actuator, an electrically-switchable vacuum valve, avacuum-driven actuator, an electrically-switchable pyrotechnic-drivenactuator, an electrically-switchable explosive-charged actuator, anelectrically-switchable compressed-gas-driven actuator, and combinationsthereof.
 11. The method of claim 3, wherein the determining whether theoutput signal meets or exceeds the predetermined threshold level isperformed by an electrical circuit comprising a component selected fromthe group consisting of a microprocessor, a capacitor, a resistor, atransistor, an analog electrical circuit, an analog-to-digitalconverter, a digital-to-analog converter, an amplifier, and combinationsthereof.
 12. The method of claim 2, wherein at least some of the ratchetteeth are formed along a curved path.
 13. The method of claim 2, whereinat least some of the ratchet teeth are formed along a linear path. 14.The method of claim 2, wherein the ratchet mechanism comprises: a firstslider portion; and a second slider portion slidably coupled to thefirst slider portion.
 15. The method of claim 2, wherein the ratchetmechanism is attached to and part of a shock absorber device.
 16. Themethod of claim 2, wherein the ratchet mechanism comprises a ratchetgear extending from a suspension arm and extending circumferentially atleast partially around a pivot axis of the suspension arm, wherein theratchet gear is fixed relative to the suspension arm and adapted topivot with the suspension arm about the pivot axis.
 17. The method ofclaim 2, wherein the tongue member is part of a movable tongue system,and wherein the ratchet mechanism comprises: a first arm; a second armpivotably coupled to the first arm, at least part of the movable tonguesystem being attached to the second arm; and a tooth arm extending fromthe first arm, the tooth arm having the set of ratchet teeth thereon,and the tooth arm extending across at least part of the movable tonguesystem.
 18. A method of limiting expansion of a spring member on avehicle, wherein the spring member is biased between a sprung massportion of the vehicle and an unsprung mass portion of the vehicle, themethod comprising: measuring lateral acceleration of the vehicle;determining whether the lateral acceleration of the vehicle exceeds apredetermined threshold level; and if the lateral acceleration exceedsthe predetermined threshold level, then for a predetermined period oftime, allowing the spring member to be compressed when the unsprung massportion moves toward the sprung mass portion, but not allowing thespring member to expand.
 19. The method of claim 18, wherein themeasuring lateral acceleration is performed by an accelerometer.
 20. Themethod of claim 18, wherein the determining whether the lateralacceleration of the vehicle exceeds the predetermined threshold level isperformed by a microprocessor.
 21. The method of claim 18, wherein thedetermining whether the lateral acceleration of the vehicle exceeds thepredetermined threshold level is performed by analog electricalcircuitry.
 22. The method of claim 21, wherein the analog electricalcircuitry comprises a resistor, a capacitor, and a transistor.
 23. Themethod of claim 18, wherein the method is performed only if the vehicleis moving at a speed greater than a predetermined speed level, andwherein the method further comprises measuring and monitoring the speedof the vehicle.
 24. The method of claim 23, wherein the predeterminedthreshold level for lateral acceleration is about 6.4 ft/sec² and thepredetermined speed level is about 30 miles per hour.
 25. The method ofclaim 18, wherein the predetermined period of time is about 1 second.26. The method of claim 18, wherein the allowing the spring member to becompressed when the unsprung mass portion moves toward the sprung massportion, but not allowing the spring member to expand, comprises:activating an electro-mechanical actuator of a movable tongue system;and using the electro-mechanical actuator, moving a tongue member of themovable tongue system toward a first slider portion of a first slidermechanism and into a series of teeth formed along the first sliderportion, wherein the first slider portion is slidably coupled to asecond slider portion of the first slider mechanism, and wherein themovable tongue system is attached to the second slider portion.
 27. Amethod of improving vehicle stability during abrupt turning maneuvers,comprising: obtaining a lateral acceleration measurement of a vehicle;if the lateral acceleration measurement exceeds a predetermined lateralacceleration level, then for a predetermined period of time, activatingan electro-mechanical actuator, the electro-mechanical actuator beingpart of a moveable tongue system, wherein the moveable tongue systemfurther comprises a tongue member; using the electro-mechanical actuatorwhen activated, driving the tongue member against a first slider portionof a first slider mechanism at a location upon a path of movement for aseries of teeth formed along the first slider portion, wherein the firstslider portion is slidably coupled to a second slider portion of thefirst slider mechanism, wherein the movable tongue system is attached tothe second slider portion, wherein the first slider mechanism ismechanically coupled between a sprung mass portion and an unsprung massportion of the vehicle, wherein a vehicle wheel is rotatably coupled tothe unsprung mass portion, wherein a spring member is biased between thesprung mass portion and the unsprung mass portion of the vehicle; andwhen the tongue member is driven against the first slider portion andwhen the tongue member engages into the series of teeth, preventing thespring member from expanding.
 28. The method of claim 27, when thetongue member is driven against the first slider portion and when thetongue member engages into the series of teeth, allowing the springmember to be compressed.
 29. The method of claim 27, wherein theobtaining the lateral acceleration measurement is performed by anacceleration measuring device comprising an accelerometer.
 30. Themethod of claim 27, wherein the determining if the lateral accelerationmeasurement exceeds the predetermined lateral acceleration level isperformed by a triggering device comprising a microprocessor.